Tags: medium



Saturday, October 6th, 2018

An nth-letter selector in CSS

Variable fonts are a very exciting and powerful new addition to the toolbox of web design. They was very much at the centre of discussion at this year’s Ampersand conference.

A lot of the demonstrations of the power of variable fonts are showing how it can be used to make letter-by-letter adjustments. The Ampersand website itself does this with the logo. See also: the brilliant demos by Mandy. It’s getting to the point where logotypes can be sculpted and adjusted just-so using CSS and raw text—no images required.

I find this to be thrilling, but there’s a fly in the ointment. In order to style something in CSS, you need a selector to target it. If you’re going to style individual letters, you need to wrap each one in an HTML element so that you can then select it in CSS.

For the Ampersand logo, we had to wrap each letter in a span (and then, becuase that might cause each letter to be read out individually instead of all of them as a single word, we applied some ARIA shenanigans to the containing element). There’s even a JavaScript library—Splitting.js—that will do this for you.

But if the whole point of using HTML is that the content is accessible, copyable, and pastable, isn’t a bit of a shame that we then compromise the markup—and the accessibility—by wrapping individual letters in presentational tags?

What if there were an ::nth-letter selector in CSS?

There’s some prior art here. We’ve already got ::first-letter (and now the initial-letter property or whatever it ends up being called). If we can target the first letter in a piece of text, why not the second, or third, or nth?

It raises some questions. What constitutes a letter? Would it be better if we talked about ::first-character, ::initial-character, ::nth-character, and so on?

Even then, there are some tricksy things to figure out. What’s the third character in this piece of markup?


Is it “C”, becuase that’s the third character regardless of nesting? Or is it “E”, becuase techically that’s the third character token that’s a direct child of the parent element?

I imagine that implementing ::nth-letter (or ::nth-character) would be quite complex so there would probably be very little appetite for it from browser makers. But it doesn’t seem as problematic as some selectors we’ve already got.

Take ::first-line, for example. That violates one of the biggest issues in adding new CSS selectors: it’s a selector that depends on layout.

Think about it. The browser has to first calculate how many characters are in the first line of an element (like, say, a paragraph). Having figured that out, the browser can then apply the styles declared in the ::first-line selector. But those styles may involve font sizing updates that changes the number of characters in the first line. Paradox!

(Technically, only a subset of CSS of properties can be applied to ::first-line, but that subset includes font-size so the paradox remains.)

I checked to see if ::first-line was included in one of my favourite documents: Incomplete List of Mistakes in the Design of CSS. It isn’t.

So compared to the logic-bending paradoxes of ::first-line, an ::nth-letter selector would be relatively straightforward. But that in itself isn’t a good enough reason for it to exist. As the CSS Working Group FAQs say:

The fact that we’ve made one mistake isn’t an argument for repeating the mistake.

A new selector needs to solve specific use cases. I would argue that all the letter-by-letter uses of variable fonts that we’re seeing demonstrate the use cases, and the number of these examples is only going to increase. The very fact that JavaScript libraries exist to solve this problem shows that there’s a need here (and we’ve seen the pattern of common JavaScript use-cases ending up in CSS before—rollovers, animation, etc.).

Now, I know that browser makers would like us to figure out how proposed CSS features should work by polyfilling a solution with Houdini. But would that work for a selector? I don’t know much about Houdini so I asked Una. She pointed me to a proposal by Greg and Tab for a full-on parser in Houdini. But that’s a loooong way off. Until then, we must petition our case to the browser gods.

This is not a new suggestion.

Anne Van Kesteren proposed ::nth-letter way back in 2003:

While I’m talking about CSS, I would also like to have ::nth-line(n), ::nth-letter(n) and ::nth-word(n), any thoughts?

Trent called for ::nth-letter in January 2011:

I think this would be the ideal solution from a web designer’s perspective. No javascript would be required, and 100% of the styling would be handled right where it should be—in the CSS.

Chris repeated the call in October of 2011:

Of all of these “new” selectors, ::nth-letter is likely the most useful.

In 2012, Bram linked to a blog post (now unavailable) from Adobe indicating that they were working on ::nth-letter for Webkit. That was the last anyone’s seen of this elusive pseudo-element.

In 2013, Chris (again) included ::nth-letter in his wishlist for CSS. So say we all.

Thursday, October 4th, 2018


I like the robustness that comes with declarative languages. I also like the power that comes with imperative languages. Best of all, I like having the choice.

Take the video and audio elements, for example. If you want, you can embed a video or audio file into a web page using a straightforward declaration in HTML.

<audio src="..." controls><!-- fallback goes here --></audio>

Straightaway, that covers 80%-90% of use cases. But if you need to do more—like, provide your own custom controls—there’s a corresponding API that’s exposed in JavaScript. Using that API, you can do everything that you can do with the HTML element, and a whole lot more besides.

It’s a similar story with animation. CSS provides plenty of animation power, but it’s limited in the events that can trigger the animations. That’s okay. There’s a corresponding JavaScript API that gives you more power. Again, the CSS declarations cover 80%-90% of use cases, but for anyone in that 10%-20%, the web animation API is there to help.

Client-side form validation is another good example. For most us, the HTML attributes—required, type, etc.—are probably enough most of the time.

<input type="email" required />

When we need more fine-grained control, there’s a validation API available in JavaScript (yes, yes, I know that the API itself is problematic, but you get the point).

I really like this design pattern. Cover 80% of the use cases with a declarative solution in HTML, but also provide an imperative alternative in JavaScript that gives more power. HTML5 has plenty of examples of this pattern. But I feel like the history of web standards has a few missed opportunities too.

Geolocation is a good example of an unbalanced feature. If you want to use it, you must use JavaScript. There is no declarative alternative. This doesn’t exist:

<input type="geolocation" />

That’s a shame. Anyone writing a form that asks for the user’s location—in order to submit that information to a server for processing—must write some JavaScript. That’s okay, I guess, but it’s always going to be that bit more fragile and error-prone compared to markup.

(And just in case you’re thinking of the fallback—which would be for the input element to be rendered as though its type value were text—and you think it’s ludicrous to expect users with non-supporting browsers to enter latitude and longitude coordinates by hand, I direct your attention to input type="color": in non-supporting browsers, it’s rendered as input type="text" and users are expected to enter colour values by hand.)

Geolocation is an interesting use case because it only works on HTTPS. There are quite a few JavaScript APIs that quite rightly require a secure context—like service workers—but I can’t think of a single HTML element or attribute that requires HTTPS (although that will soon change if we don’t act to stop plans to create a two-tier web). But that can’t have been the thinking behind geolocation being JavaScript only; when geolocation first shipped, it was available over HTTP connections too.

Anyway, that’s just one example. Like I said, it’s not that I’m in favour of declarative solutions instead of imperative ones; I strongly favour the choice offered by providing declarative solutions as well as imperative ones.

In recent years there’s been a push to expose low-level browser features to developers. They’re inevitably exposed as JavaScript APIs. In most cases, that makes total sense. I can’t really imagine a declarative way of accessing the fetch or cache APIs, for example. But I think we should be careful that it doesn’t become the only way of exposing new browser features. I think that, wherever possible, the design pattern of exposing new features declaratively and imperatively offers the best of the both worlds—ease of use for the simple use cases, and power for the more complex use cases.

Previously, it was up to browser makers to think about these things. But now, with the advent of web components, we developers are gaining that same level of power and responsibility. So if you’re making a web component that you’re hoping other people will also use, maybe it’s worth keeping this design pattern in mind: allow authors to configure the functionality of the component using HTML attributes and JavaScript methods.

Monday, September 24th, 2018

Preparing a conference talk

I gave a talk at the State Of The Browser conference in London earlier this month. It was a 25 minute spiel called The Web Is Agreement.

While I was putting the talk together, I posted some pictures of my talk preparation process. People seemed to be quite interested in that peek behind the curtain, so I thought I’d jot down the process I used.

There are two aspects to preparing a talk: the content and the presentation. I like to keep the preparation of those two parts separate. It’s kind of like writing: instead of writing and editing at the same time, it’s more productive to write any old crap first (to get it out of your head) and then go back and edit—“write drunk and edit sober”. Separating out those two mindsets allows you to concentrate on the task at hand.

So, to begin with, I’m not thinking about how I’m going to present the material at all. I’m only concerned with what I want to say.

When it comes to preparing the subject matter for a talk, step number zero is to banish your inner critic. You know who I mean. That little asshole with the sneering voice that says things like “you’re not qualified to talk about this” or “everything has already been said.” Find a way to realise that this demon is a) speaking from inside your head and b) not real. Maybe try drawing your inner critic. Ridiculous? Yes. Yes, it is.

Alright, time to start. There’s nothing more intimidating than a blank slidedeck, except maybe a blank Photoshop file, or a blank word processing document. In each of those cases, I find that starting with software is rarely a good idea. Paper is your friend.

I get a piece of A3 paper and start scribbling out a mind map. “Mind map” is a somewhat grandiose term for what is effectively a lo-fi crazy wall.

Mind mapping.
Step 1

The idea here is to get everything out of my head. Don’t self-censor. At this stage, there are no bad ideas. This is a “yes, and…” exercise, not a “no, but…” exercise. Divergent, not convergent.

Not everything will make it into the final talk. That’s okay. In fact, I often find that there’s one thing that I’m really attached to, that I’m certain will be in the talk, that doesn’t make the cut. Kill your darlings.

I used to do this mind-mapping step by opening a text file and dumping my thoughts into it. I told myself that they were in no particular order, but because a text file reads left to right and top to bottom, they are in an order, whether I intended it or not. By using a big sheet of paper, I can genuinely get things down in a disconnected way (and later, I can literally start drawing connections).

For this particular talk, I knew that the subject matter would be something to do with web standards. I brain-dumped every vague thought I had about standards in general.

The next step is what I call chunking. I start to group related ideas together. Then I give a label to each of these chunks. Personally, I like to use a post-it note per chunk. I put one word or phrase on the post-it note, but it could just as easily be a doodle. The important thing is that you know what the word or doodle represents. Each chunk should represent a self-contained little topic that you might talk about for 3 to 5 minutes.

Step 2

At this point, I can start thinking about the structure of the talk: “Should I start with this topic? Or should I put that in the middle?” The cost of changing my mind is minimal—I’m just moving post-it notes around.

With topics broken down into chunks like this, I can flesh out each one. The nice thing about this is that I’ve taken one big overwhelming task—prepare a presentation!—and I’ve broken it down into smaller, more manageable tasks. I can take a random post-it note and set myself, say, ten or fifteen minutes to jot down an explanation of it.

The explanation could just be bullet points. For this particular talk, I decided to write full sentences.

Step 3

Even though, in this case, I was writing out my thoughts word for word, I still kept the topics in separate files. That way, I can still move things around easily.

Crafting the narrative structure of a talk is the part I find most challenging …but it’s also the most rewarding. By having the content chunked up like this, I can experiment with different structures. I like to try out different narrative techniques from books and films, like say, flashback: find the most exciting part of the talk; start with that, and then give the backstory that led up to it. That’s just one example. There are many possible narrative stuctures.

What I definitely don’t do is enact the advice that everyone is given for their college presentations:

  1. say what you’re going to say,
  2. say it, and
  3. recap what you’ve said.

To me, that’s the equivalent of showing an audience the trailer for a film right before watching the film …and then reading a review of the film right after watching it. Just play the film! Give the audience some credit—assume the audience has no knowledge but infinite intelligence.

Oh, and there’s one easy solution to cracking the narrative problem: make a list. If you’ve got 7 chunks, you can always give a talk on “Seven things about whatever” …but it’s a bit of a cop-out. I mean, most films have a three-act structure, but they don’t start the film by telling the audience that, and they don’t point out when one act finishes and another begins. I think it’s much more satisfying—albeit more challenging—to find a way to segue from chunk to chunk.

Finding the narrative thread is tricky work, but at least, by this point, it’s its own separate task: if I had tried to figure out the narrative thread at the start of the process, or even when I was chunking things out, it would’ve been overwhelming. Now it’s just the next task in my to-do list.

I suppose, at this point, I might as well make some slides.

Step 4

I’m not trying to be dismissive of slides—I think having nice slides is a very good thing. But I do think that they can become the “busy work” of preparing a presentation. If I start on the slides too soon, I find they’ll take up all my time. I think it’s far more important to devote time to the content and structure of the talk. The slides should illustrate the talk …but the slides are not the talk.

If you don’t think of the slides as being subservient to the talk, there’s a danger that you’ll end up with a slidedeck that’s more for the speaker’s benefit than the audience’s.

It’s all too easy to use the slides as a defence mechanism. You’re in a room full of people looking towards you. It’s perfectly reasonable for your brain to scream, “Don’t look at me! Look at the slides!” But taken too far, that can be interpreted as “Don’t listen to me!”

For this particular talk, there were moments when I wanted to make sure the audience was focused on some key point I was making. I decided that having no slide at all was the best way of driving home my point.

But slidedeck style is quite a personal thing, so use whatever works for you.

It’s a similar story with presentation style. Apart from some general good advice—like, speak clearly—the way you present should be as unique as you are. I have just one piece of advice, and it’s this: read Demystifying Public Speaking by Lara Hogan—it’s really, really good!

(I had to apologise to Lara last time I saw her, because I really wanted her to sign my copy of her book …but I didn’t have it, because it’s easily the book I’ve loaned out to other people the most.)

I did a good few run-throughs of my talk. There were a few sentences that sounded fine written down, but were really clumsy to say out loud. It reminded me of what Harrison Ford told George Lucas during the filming of Star Wars: “You can type this shit, George, but you can’t say it.”

I gave a final run-through at work to some of my Clearleft colleagues. To be honest, I find that more nerve-wracking than speaking on a stage in front of a big room full of strangers. I think it’s something to do with the presentation of self.

Finally, the day of the conference rolled around, and I was feeling pretty comfortable with my material. I’m pretty happy with how it turned out. You can read The Web Is Agreement, and you can look at the slides, but as with any conference talk, you kinda had to be there.

Sunday, September 23rd, 2018

Service workers in Samsung Internet browser

I was getting reports of some odd behaviour with the service worker on thesession.org, the Irish music website I run. Someone emailed me to say that they kept getting the offline page, even when their internet connection was perfectly fine and the site was up and running.

They didn’t mind answering my pestering follow-on questions to isolate the problem. They told me that they were using the Samsung Internet browser on Android. After a little searching, I found this message on a Github thread about using waitUntil. It’s from someone who works on the Samsung Internet team:

Sadly, the asynchronos waitUntil() is not implemented yet in our browser. Yes, we will implement it but our release cycle is so far. So, for a long time, we might not resolve the issue.

A-ha! That explains the problem. See, here’s the pattern I was using:

  1. When someone requests a file,
  2. fetch that file from the network,
  3. create a copy of the file and cache it,
  4. return the contents.

Step 1 is the event listener:

// 1. When someone requests a file
addEventListener('fetch', fetchEvent => {
  let request = fetchEvent.request;

Steps 2, 3, and 4 are inside that respondWith:

// 2. fetch that file from the network
.then( responseFromFetch => {
  // 3. create a copy of the file and cache it
  let copy = responseFromFetch.clone();
  .then( cache => {
    cache.put(request, copy);
  // 4. return the contents.
  return responseFromFetch;

Step 4 might well complete while step 3 is still running (remember, everything in a service worker script is asynchronous so even though I’ve written out the steps sequentially, you never know what order the steps will finish in). That’s why I’m wrapping that third step inside fetchEvent.waitUntil:

// 2. fetch that file from the network
.then( responseFromFetch => {
  // 3. create a copy of the file and cache it
  let copy = responseFromFetch.clone();
    .then( cache => {
      cache.put(request, copy);
  // 4. return the contents.
  return responseFromFetch;

If a browser (like Samsung Internet) doesn’t understand the bit where I say fetchEvent.waitUntil, then it will throw an error and execute the catch clause. That’s where I have my fifth and final step: “try looking in the cache instead, but if that fails, show the offline page”:

.catch( fetchError => {
  return caches.match(request)
  .then( responseFromCache => {
    return responseFromCache || caches.match('/offline');

Normally in this kind of situation, I’d use feature detection to check whether a browser understands a particular API method. But it’s a bit tricky to test for support for asynchronous waitUntil. That’s okay. I can use a try/catch statement instead. Here’s what my revised code looks like:

.then( responseFromFetch => {
  let copy = responseFromFetch.clone();
  try {
      .then( cache => {
        cache.put(request, copy);
  } catch (error) {
  return responseFromFetch;

Now I’ve managed to localise the error. If a browser doesn’t understand the bit where I say fetchEvent.waitUntil, it will execute the code in the catch clause, and then carry on as usual. (I realise it’s a bit confusing that there are two different kinds of catch clauses going on here: on the outside there’s a .then()/.catch() combination; inside is a try{}/catch{} combination.)

At some point, when support for async waitUntil statements is universal, this precautionary measure won’t be needed, but for now wrapping them inside try doesn’t do any harm.

There are a few places in chapter five of Going Offline—the chapter about service worker strategies—where I show examples using async waitUntil. There’s nothing wrong with the code in those examples, but if you want to play it safe (especially while Samsung Internet doesn’t support async waitUntil), feel free to wrap those examples in try/catch statements. But I’m not going to make those changes part of the errata for the book. In this case, the issue isn’t with the code itself, but with browser support.

Thursday, September 20th, 2018

A framework for web performance

Here at Clearleft, we’ve recently been doing some front-end consultancy. That prompted me to jot down thoughts on design principles and performance:

We continued with some more performance work this week. Having already covered some of the nitty-gritty performance tactics like font-loading, image optimisation, etc., we wanted to take a step back and formulate an ongoing strategy for performance.

When it comes to web performance, the eternal question is “What should we measure?” The answer to that question will determine where you then concentrate your efforts—whatever it is your measuring, that’s what you’ll be looking to improve.

I started by drawing a distinction between measurements of quantities and measurements of time. Quantities are quite easy to measure. You can measure these quantities using nothing more than browser dev tools:

  • overall file size (page weight + assets), and
  • number of requests.

I think it’s good to measure these quantities, and I think it’s good to have a performance budget for them. But I also think they’re table stakes. They don’t actually tell you much about the impact that performance is having on the user experience. For that, we need to enumerate moments in time:

  • time to first byte,
  • time to first render,
  • time to first meaningful paint, and
  • time to first meaningful interaction.

There’s one more moment in time, which is the time until DOM content is loaded. But I’m not sure that has a direct effect on how performance is perceived, so it feels like it belongs more in the category of quantities than time.

Next, we listed out all the factors that could affect each of the moments in time. For example, the time to first byte depends on the speed of the network that the user is on. It also depends on how speedily your server (or Content Delivery Network) can return a response. Meanwhile, time to first render is affected by the speed of the user’s network, but it’s also affected by how many blocking elements are on the critical path.

By listing all the factors out, we can draw a distinction between the factors that are outside of our control, and the factors that we can do something about. So while we might not be able to do anything about the speed of the user’s network, we might well be able to optimise the speed at which our server returns a response, or we might be able to defer some assets that are currently blocking the critical path.

1st byte
  • server speed
  • network speed
1st render
  • network speed
  • critical path assets
1st meaningful paint
  • network speed
  • font-loading strategy
  • image optimisation
1st meaningful interaction
  • network speed
  • device processing power
  • JavaScript size

So far, everything in our list of performance-affecting factors is related to the first visit. It’s worth drawing up a second list to document all the factors for subsequent visits. This will look the same as the list for first visits, but with the crucial difference that caching now becomes a factor.

First visit factors Repeat visit factors
1st byte
  • server speed
  • network speed
  • server speed
  • network speed
  • caching
1st render
  • network speed
  • critical path assets
  • network speed
  • critical path assets
  • caching
1st meaningful paint
  • network speed
  • font-loading strategy
  • image optimisation
  • network speed
  • font-loading strategy
  • image optimisation
  • caching
1st meaningful interaction
  • network speed
  • device processing power
  • JavaScript size
  • network speed
  • device processing power
  • JavaScript size
  • caching

Alright. Now it’s time to get some numbers for each of the four moments in time. I use Web Page Test for this. Choose a realistic setting, like 3G on an Android from the East coast of the USA. Under advanced settings, be sure to select “First View and Repeat View” so that you can put those numbers in two different columns.

Here are some numbers for adactio.com:

First visit time Repeat visit time
1st byte 1.476 seconds 1.215 seconds
1st render 2.633 seconds 1.930 seconds
1st meaningful paint 2.633 seconds 1.930 seconds
1st meaningful interaction 2.868 seconds 2.083 seconds

I’m getting the same numbers for first render as first meaningful paint. That tells me that there’s no point in trying to optimise my font-loading, for example …which makes total sense, because adactio.com isn’t using any web fonts. But on a different site, you might see a big gap between those numbers.

I am seeing a gap between time to first byte and time to first render. That tells me that I might be able to get some blocking requests off the critical path. Sure enough, I’m currently referencing an external stylesheet in the head of adactio.com—if I were to inline critical styles and defer the loading of that stylesheet, I should be able to narrow that gap.

A straightforward site like adactio.com isn’t going to have much to worry about when it comes to the time to first meaningful interaction, but on other sites, this can be a significant bottleneck. If you’re sending UI elements in the initial HTML, but then waiting for JavaScript to “hydrate” those elements into working, the user can end up in an uncanny valley of tapping on page elements that look fine, but aren’t ready yet.

My point is, you’re going to see very different distributions of numbers depending on the kind of site you’re testing. There’s no one-size-fits-all metric to focus on.

Now that you’ve got numbers for how your site is currently performing, you can create two new columns: one of those is a list of first-visit targets, the other is a list of repeat-visit targets for each moment in time. Try to keep them realistic.

For example, if I could reduce the time to first render on adactio.com by 0.5 seconds, my goals would look like this:

First visit goal Repeat visit goal
1st byte 1.476 seconds 1.215 seconds
1st render 2.133 seconds 1.430 seconds
1st meaningful paint 2.133 seconds 1.430 seconds
1st meaningful interaction 2.368 seconds 1.583 seconds

See how the 0.5 seconds saving cascades down into the other numbers?

Alright! Now I’ve got something to aim for. It might also be worth having an extra column to record which of the moments in time are high priority, which are medium priority, and which are low priority.

1st byte Medium
1st render High
1st meaningful paint Low
1st meaningful interaction Low

Your goals and priorities may be quite different.

I think this is a fairly useful framework for figuring out where to focus when it comes to web performance. If you’d like to give it a go, I’ve made a web performance chart for you to print out and fill in. Here’s a PDF version if that’s easier for printing. Or you can download the HTML version if you want to edit it.

I have to say, I’m really enjoying the front-end consultancy work we’ve been doing at Clearleft around performance and related technologies, like offline functionality. I’d like to do more of it. If you’d like some help in prioritising performance at your company, please get in touch. Let’s make the web faster together.

Thursday, September 13th, 2018

The power of self-publishing - HankChizlJaw

This is something I struggle to articulate to friends who are suffering because they feel tied to silos like Facebook and Twitter:

What self-publishing does is provide me a choice, which makes me feel good. I feel like I can step away from platforms at will and I don’t feel as shackled as I have done previously.

Wednesday, September 12th, 2018

Several people are writing

Anne Gibson writes:

It sounds easy to make writing a habit, but like every other habit that doesn’t involve addictive substances like nicotine or dopamine it’s hard to start and easy to quit.

Alice Bartlett writes:

Anyway, here we are, on my blog, or in your RSS reader. I think I’ll do weaknotes. Some collections of notes. Sometimes. Not very well written probably. Generally written with the urgency of someone who is waiting for a baby wake up.

Patrick Rhone writes:

Bottom line; please place any idea worth more than 280 characters and the value Twitter places on them (which is zero) on a blog that you own and/or can easily take your important/valuable/life-changing ideas with you and make them easy for others to read and share.

Sara Soueidan writes:

What you write might help someone understand a concept that you may think has been covered enough before. We each have our own unique perspectives and writing styles. One writing style might be more approachable to some, and can therefore help and benefit a large (or even small) number of people in ways you might not expect.

Just write.

Even if only one person learns something from your article, you’ll feel great, and that you’ve contributed — even if just a little bit — to this amazing community that we’re all constantly learning from. And if no one reads your article, then that’s also okay. That voice telling you that people are just sitting somewhere watching our every step and judging us based on the popularity of our writing is a big fat pathetic attention-needing liar.

Laura Kalbag writes:

The web can be used to find common connections with folks you find interesting, and who don’t make you feel like so much of a weirdo. It’d be nice to be able to do this in a safe space that is not being surveilled.

Owning your own content, and publishing to a space you own can break through some of these barriers. Sharing your own weird scraps on your own site makes you easier to find by like-minded folks.

Brendan Dawes writes:

At times I think “will anyone reads this, does anyone care?”, but I always publish it anyway — and that’s for two reasons. First it’s a place for me to find stuff I may have forgotten how to do. Secondly, whilst some of this stuff is seemingly super-niche, if one person finds it helpful out there on the web, then that’s good enough for me. After all I’ve lost count of how many times I’ve read similar posts that have helped me out.

Robin Rendle writes:

My advice after learning from so many helpful people this weekend is this: if you’re thinking of writing something that explains a weird thing you struggled with on the Internet, do it! Don’t worry about the views and likes and Internet hugs. If you’ve struggled with figuring out this thing then be sure to jot it down, even if it’s unedited and it uses too many commas and you don’t like the tone of it.

Khoi Vinh writes:

Maybe you feel more comfortable writing in short, concise bullets than at protracted, grandiose length. Or maybe you feel more at ease with sarcasm and dry wit than with sober, exhaustive argumentation. Or perhaps you prefer to knock out a solitary first draft and never look back rather than polishing and tweaking endlessly. Whatever the approach, if you can do the work to find a genuine passion for writing, what a powerful tool you’ll have.

Amber Wilson writes:

I want to finally begin writing about psychology. A friend of mine shared his opinion that writing about this is probably best left to experts. I tried to tell him I think that people should write about whatever they want. He argued that whatever he could write about psychology has probably already been written about a thousand times. I told him that I’m going to be writer number 1001, and I’m going to write something great that nobody has written before.

Austin Kleon writes:

Maybe I’m weird, but it just feels good. It feels good to reclaim my turf. It feels good to have a spot to think out loud in public where people aren’t spitting and shitting all over the place.

Tim Kadlec writes:

I write to understand and remember. Sometimes that will be interesting to others, often it won’t be.

But it’s going to happen. Here, on my own site.

You write…

Tuesday, September 11th, 2018

The top four web performance challenges

Danielle and I have been doing some front-end consultancy for a local client recently.

We’ve both been enjoying it a lot—it’s exhausting but rewarding work. So if you’d like us to come in and spend a few days with your company’s dev team, please get in touch.

I’ve certainly enjoyed the opportunity to watch Danielle in action, leading a workshop on refactoring React components in a pattern library. She’s incredibly knowledgable in that area.

I’m clueless when it comes to React, but I really enjoy getting down to the nitty-gritty of browser features—HTML, CSS, and JavaScript APIs. Our skillsets complement one another nicely.

This recent work was what prompted my thoughts around the principles of robustness and least power. We spent a day evaluating a continuum of related front-end concerns: semantics, accessibility, performance, and SEO.

When it came to performance, a lot of the work was around figuring out the most suitable metric to prioritise:

  • time to first byte,
  • time to first render,
  • time to first meaningful paint, or
  • time to first meaningful interaction.

And that doesn’t even cover the more easily-measurable numbers like:

  • overall file size,
  • number of requests, or
  • pagespeed insights score.

One outcome was to realise that there’s a tendency (in performance, accessibility, or SEO) to focus on what’s easily measureable, not because it’s necessarily what matters, but precisely because it is easy to measure.

Then we got down to some nuts’n’bolts technology decisions. I took a step back and looked at the state of performance across the web. I thought it would be fun to rank the most troublesome technologies in order of tricksiness. I came up with a top four list.

Here we go, counting down from four to the number one spot…

4. Web fonts

Coming in at number four, it’s web fonts. Sometimes it’s the combined weight of multiple font files that’s the problem, but more often that not, it’s the perceived performance that suffers (mostly because of when the web fonts appear).

Fortunately there’s a straightforward question to ask in this situation: WWZD—What Would Zach Do?

3. Images

At the number three spot, it’s images. There are more of them and they just seem to be getting bigger all the time. And yet, we have more tools at our disposal than ever—better file formats, and excellent browser support for responsive images. Heck, we’re even getting the ability to lazy load images in HTML now.

So, as with web fonts, it feels like the impact of images on performance can be handled, as long as you give them some time and attention.

2. Our JavaScript

Just missing out on making the top spot is the JavaScript that we send down the pipe to our long-suffering users. There’s nothing wrong with the code itself—I’m sure it’s very good. There’s just too damn much of it. And that’s a real performance bottleneck, especially on mobile.

So stop sending so much JavaScript—a solution as simple as Monty Python’s instructions for playing the flute.

1. Other people’s JavaScript

At number one with a bullet, it’s all the crap that someone else tells us to put on our websites. Analytics. Ads. Trackers. Beacons. “It’s just one little script”, they say. And then that one little script calls in another, and another, and another.

It’s so disheartening when you’ve devoted your time and energy into your web font loading strategy, and optimising your images, and unbundling your JavaScript …only to have someone else’s JavaScript just shit all over your nice performance budget.

Here’s the really annoying thing: when I go to performance conferences, or participate in performance discussions, you know who’s nowhere to be found? The people making those third-party scripts.

The narrative around front-end performance is that it’s up to us developers to take responsibility for how our websites perform. But by far the biggest performance impact comes from third-party scripts.

There is a solution to this, but it’s not a technical one. We could refuse to add overweight (and in many cases, unethical) third-party scripts to the sites we build.

I have many, many issues with Google’s AMP project, but I completely acknowledge that it solves a political problem:

No external JavaScript is allowed in an AMP HTML document. This covers third-party libraries, advertising and tracking scripts. This is A-okay with me.

The reasons given for this ban are related to performance and I agree with them completely. Big bloated JavaScript libraries are one of the biggest performance killers on the web.

But how can we take that lesson from AMP and apply it to all our web pages? If we simply refuse to be the one to add those third-party scripts, we get fired, and somebody else comes in who is willing to poison web pages with third-party scripts. There’s nothing to stop companies doing that.


Suppose we were to all make a pact that we would stand in solidarity with any of our fellow developers in that sort of situation. A sort of joining-together. A union, if you will.

There is power in a factory, power in the land, power in the hands of the worker, but it all amounts to nothing if together we don’t stand.

There is power in a union.

Monday, September 10th, 2018

Robustness and least power

There’s a great article by Steven Garrity over on A List Apart called Design with Difficult Data. It runs through the advantages of using unusual content to stress-test interfaces, referencing Postel’s Law, AKA the robustness principle:

Be conservative in what you send, be liberal in what you accept.

Even though the robustness principle was formulated for packet-switching, I see it at work in all sorts of disciplines, including design. A good example is in best practices for designing forms:

Every field you ask users to fill out requires some effort. The more effort is needed to fill out a form, the less likely users will complete the form. That’s why the foundational rule of form design is shorter is better — get rid of all inessential fields.

In other words, be conservative in the number of form fields you send to users. But then, when it comes to users filling in those fields:

It’s very common for a few variations of an answer to a question to be possible; for example, when a form asks users to provide information about their state, and a user responds by typing their state’s abbreviation instead of the full name (for example, CA instead of California). The form should accept both formats, and it’s the developer job to convert the data into a consistent format.

In other words, be liberal in what you accept from users.

I find the robustness principle to be an immensely powerful way of figuring out how to approach many design problems. When it comes to figuring out what specific tools or technologies to use, there’s an equally useful principle: the rule of least power:

Choose the least powerful language suitable for a given purpose.

On the face of it, this sounds counter-intuitive; why forego a powerful technology in favour of something less powerful?

Well, power comes with a price. Powerful technologies tend to be more complex, which means they can be trickier to use and trickier to swap out later.

Take the front-end stack, for example: HTML, CSS, and JavaScript. HTML and CSS are declarative, so you don’t get as much precise control as you get with an imperative language like JavaScript. But JavaScript comes with a steeper learning curve and a stricter error-handling model than HTML or CSS.

As a general rule, it’s always worth asking if you can accomplish something with a less powerful technology:

In the web front-end stack — HTML, CSS, JS, and ARIA — if you can solve a problem with a simpler solution lower in the stack, you should. It’s less fragile, more foolproof, and just works.

  • Instead of using JavaScript to do animation, see if you can do it in CSS instead.
  • Instead of using JavaScript to do simple client-side form validation, try to use HTML input types and attributes like required.
  • Instead of using ARIA to give a certain role value to a div or span, try to use a more suitable HTML element instead.

It sounds a lot like the KISS principle: Keep It Simple, Stupid. But whereas the KISS principle can be applied within a specific technology—like keeping your CSS manageable—the rule of least power is all about evaluating technology; choosing the most appropriate technology for the task at hand.

There are some associated principles, like YAGNI: You Ain’t Gonna Need It. That helps you avoid picking a technology that’s too powerful for your current needs, but which might be suitable in the future: premature optimisation. Or, as Rachel put it, stop solving problems you don’t yet have:

So make sure every bit of code added to your project is there for a reason you can explain, not just because it is part of some standard toolkit or boilerplate.

There’s no shortage of principles, laws, and rules out there, and I find many of them very useful, but if I had to pick just two that are particularly applicable to my work, they would be the robustness principle and the rule of least of power.

After all, if they’re good enough for Tim Berners-Lee…

Sunday, September 9th, 2018

The Web Is Agreement

This presentation on web standards was delivered at the State Of The Browser conference in London in September 2018.

Web standards don’t exist.

At least, they don’t physically exist. They are intangible.

They’re in good company.

Feelings are intangible, but real. Hope. Despair.

Ideas are intangible: liberty, justice, socialism, capitalism.

The economy. Currency. All intangible. I’m sure we’ve all had those “college thoughts”:

Money isn’t real, man! They’re just bits of metal and pieces of paper ! Wake up, sheeple!

Nations are intangible. Geographically, France is a tangible, physical place. But France, the Republic, is an idea. Geographically, North America is a real, tangible, physical land mass. But ideas like “Canada” and “The United States” only exist in our minds.

Faith—the feeling—is intangible.

God—the idea—is intangible.

Art—the concept—is intangible.

A piece of art is an insantiation of the intangible concept of what art is.

Incidentally, I quite like Brian Eno’s working definition of what art is. Art is anything we don’t have to do. We don’t have to make paintings, or sculptures, or films, or music. We have to clothe ourselves for practical reasons, but we don’t have to make clothes beautiful. We have to prepare food to eat it, but don’t have to make it a joyous event.

By this definition, sports are also art. We don’t have to play football. Sports are also intangible.

A game of football is an instantiation of the intangible idea of what football is.

Football, chess, rugby, quiditch and rollerball are equally (in)tangible. But football, chess and rugby have more consensus.

(Christianity, Islam, Judaism, and The Force are equally intangible, but Christianity, Islam, and Judaism have a bit more consensus than The Force).

HTML is intangible.


A web page is an instantiation of the intangible idea of what HTML is.

But we can document our shared consensus.

A rule book for football is like a web standard specification. A documentation of consensus.

By the way, economics, religions, sports and laws are all examples of intangibles that can’t be proven, because they all rely on their own internal logic—there is no outside data that can prove football or Hinduism or capitalism to be “true”. That’s very different to ideas like gravity, evolution, relativity, or germ theory—they are all intangible but provable. They are discovered, rather than created. They are part of objective reality.

Consensus reality is the collection of intangibles that we collectively agree to be true: economy, religion, law, web standards.

We treat consensus reality much the same as we treat objective reality: in our minds, football, capitalism, and Christianity are just as real as buildings, trees, and stars.

Sometimes consensus reality and objective reality get into fights.

Some people have tried to make a consensus reality around the accuracy of astrology or the efficacy of homeopathy, or ideas like the Earth being flat, 9-11 being an inside job, the moon landings being faked, the holocaust never having happened, or vaccines causing autism. These people are unfazed by objective reality, which disproves each one of these ideas.

For a long time, the consensus reality was that the sun revolved around the Earth. Copernicus and Galileo demonstrated that the objective reality was that the Earth (and all the other planets in our solar system) revolve around the sun. After the dust settled on that particular punch-up, we switched up our consensus reality. We changed the story.


That’s another way of thinking about consensus reality: our currencies, our religions, our sports and our laws are stories that we collectively choose to believe.

Web standards are a collection of intangibles that we collectively agree to be true. They’re our stories. They’re our collective consensus reality. They are what web browsers agree to implement, and what we agree to use.

The web is agreement.

The Web Is Agreement by Paul Downey.

For human beings to collaborate together, they need a shared purpose. They must have a shared consensus reality—a shared story.

Once a group of people share a purpose, they can work together to establish principles.

Design principles are points of agreement. There are design principles underlying every human endeavour. Sometimes they are tacit. Sometimes they are written down.

Patterns emerge from principles.

Patterns upon Principles upon Purpose.

Here’s an example of a human endeavour: the creation of a nation state, like the United States of America.

  1. The purpose is agreed in the declaration of independence.
  2. The principles are documented in the constitution.
  3. The patterns emerge in the form of laws.

HTML elements, CSS features, and JavaScript APIs are all patterns (that we agree upon). Those patterns are informed by design principles.

HTML, CSS, and JavaScript.

I’ve been collecting design principles of varying quality at principles.adactio.com.

Here’s one of the design principles behind HTML5. It’s my personal favourite—the priority of constituencies:

In case of conflict, consider users over authors over implementors over specifiers over theoretical purity.

“In case of conflict”—that’s exactly what a good design principle does! It establishes the boundaries of agreement. If you disagree with the design principles of a project, there probably isn’t much point contributing to that project.

Also, it’s reversible. You could imagine a different project that favoured theoretical purity above all else. In fact, that’s pretty much what XHTML 2 was all about.

XHTML 1 was simply HTML reformulated with the syntax of XML: lowercase tags, lowercase attributes, always quoting attribute values.

Remember HTML doesn’t care whether tags and attributes are uppercase or lowercase, or whether you put quotes around your attribute values. You can even leave out some closing tags.

So XHTML 1 was actually kind of a nice bit of agreement: professional web developers agreed on using lowercase tags and attributes, and we agreed to quote our attributes. Browsers didn’t care one way or the other.

But XHTML 2 was going to take the error-handling model of XML and apply it to HTML. This is the error handling model of XML: if the parser encounters a single error, don’t render the document.

Of course nobody agreed to this. Browsers didn’t agree to implement XHTML 2. Developers didn’t agree to use it. It ceased to exist.

It turns out that creating a format is relatively straightforward. But how do you turn something into a standard? The really hard part is getting agreement.

Sturgeon’s Law states:

90% of everything is crap.

Coincidentally, 90% is also the percentage of the world’s crap that gets transported by ocean. Your clothes, your food, your furniture, your electronics …chances are that at some point they were transported within an intermodal container.

These shipping containers are probably the most visible—and certainly one of the most important—standards in the physical world. Before the use of intermodal containers, loading and unloading cargo from ships was a long, laborious, and dangerous task.

Along came Malcom McLean who realised that the whole process could be made an order of magnitude more efficient if the cargo were stored in containers that could be moved from ship to truck to train.

But he wasn’t the only one. The movement towards containerisation was already happening independently around the world. But everyone was using different sized containers with different kinds of fittings. If this continued, the result would be a tower of Babel instead of smoothly running global logistics.

Malcolm McLean and his engineer Keith Tantlinger designed two crate sizes—20ft and 40ft—that would work for ships, trucks, and trains. Their design also incorporated an ingenious twistlock mechanism to secure containers together. But the extra step that would ensure that their design would win out was this: Tantlinger convinced McLean to give up the patent rights.

This wasn’t done out of any hippy-dippy ideology. These were hard-nosed businessmen. But they understood that a rising tide raises all boats, and they wanted all boats to be carrying the same kind of containers.

Without the threat of a patent lurking beneath the surface, ready to torpedo the potential benefits, the intermodal container went on to change the world economy. (The world economy is very large and intangible.)

The World Wide Web also ended up changing the world economy, and much more besides. And like the intermodal container, the World Wide Web is patent-free.

The first ever web server—Tim Berners-Lee’s NeXT machine.

Again, this was a pragmatic choice to help foster adoption. When Tim Berners-Lee and his colleague Robert Cailleau were trying to get people to use their World Wide Web project they faced some stiff competition. Lots of people were already using Gopher. Anyone remember Gopher?

The seemingly unstoppable growth of the Gopher protocol was somewhat hobbled in the early ’90s when the University of Minnesota announced that it was going to start charging fees for using it. This was a cautionary lesson for Berners-Lee and Cailleau. They wanted to make sure that CERN didn’t make the same mistake.

On April 30th, 1993, the code for the World Wide Project was made freely available.

This is for everyone.

Robert Cailleau’s copy of the document that put the World Wide Web into the public domain.

If you’re trying to get people to adopt a standard or use a new hypertext system, the biggest obstacle you’re going to face is inertia. As the brilliant computer scientist Grace Hopper used to say:

The most dangerous phrase in the English language is “We’ve always done it this way.”

Grace Hopper.

Rear Admiral Grace Hopper waged war on business as usual. She was well aware how abritrary business as usual is. Business as usual is simply the current state of our consensus reality. She said:

Humans are allergic to change.

I try to fight that.

That’s why I have a clock on my wall that runs counter‐clockwise.

Our clocks are a perfect example of a ubiquitous but arbitrary convention. Why should clocks run clockwise rather than counter-clockwise?

One neat explanation is that clocks are mimicing the movement of a shadow across the face of a sundial …in the Northern hemisphere. Had clocks been invented in the Southern hemisphere, they would indeed run counter-clockwise.

A sundial in the Southern hemisphere.

But on the clock face itself, why do we carve up time into 24 hours? Why are there 60 minutes in an hour? Why are there are 60 seconds in a minute?

24 by 60 by 60.

It probably all goes back to Babylonian accountants. Early cuneiform tablets show that they used a sexagecimal system for counting—that’s because 60 is the lowest number that can be divided evenly by 6, 5, 4, 3, 2, and 1.

But we don’t count in base 60; we count in base 10. That in itself is arbitrary—we just happen to have a total of ten digits on our hands.

So if the sexagesimal system of telling time is an accident of accounting, and base ten is more widespread, why don’t we switch to a decimal timekeeping system?

It has been tried. The French revolution introduced not just a new decimal calendar—much neater than our base 12 calendar—but also decimal time. Each day had ten hours. Each hour had 100 minutes. Each minute had 100 seconds. So much better!

10 by 100 by 100.

It didn’t take. Humans are allergic to change. Sexagesimal time may be arbitrary and messy but …we’ve always done it this way.

Incidentally, this is also why I’m not holding my breath in anticipation of the USA ever switching to the metric system.

Instead of trying to completely change people’s behaviour, you’re likely to have more success by incrementally and subtly altering what people are used to.

That was certainly the case with the World Wide Web.

The Hypertext Transfer Protocol sits on top of the existing TCP/IP stack.

The key building block of the web is the URL. But instead of creating an entirely new addressing scheme, the web uses the existing Domain Name System.

HTTP upon TCP/IP; URLs upon DNS.

Then there’s the lingua franca of the World Wide Web. These elements probably look familiar to you:

<body> <title> <p> <h1> <h2> <h3> <ol> <ul> <li> <dl> <dt> <dd>

You recognise this language, right? That’s right—it’s SGML. Standard Generalised Markup Language.

Specifically, it’s CERN SGML—a flavour of SGML that was already popular at CERN when Tim Berners-Lee was working on the World Wide Project. He used this vocabulary as the basis for the HyperText Markup Language.

Because this vocabulary was already familiar to people at CERN, convincing them to use HTML wasn’t too much of a hard sell. They could take an existing SGML document, change the file extension to .htm and it would work in one of those new fangled web browsers.


In fact, HTML worked better than expected. The initial idea was that HTML pages would be little more than indices that pointed to other files containing the real meat and potatoes of content—spreadsheets, word processing documents, whatever. But to everyone’s surprise, people started writing and publishing content in HTML.

Was HTML the best format? Far from it. But it was just good enough and easy enough to get the job done.

It has since changed, but that change has happened according to another design principle:

Evolution, not revolution

From its humble beginnings with the handful of elements borrowed from CERN SGML, HTML has grown to encompass an additional 100 elements over its lifespan. And yet, it’s still technically the same format!

This is a classic example of the paradox called the Ship Of Theseus, also known as Trigger’s Broom.

You can take an HTML document written over two decades ago, and open it in a browser today.

Even more astonishing, you can take an HTML document written today and open it in a browser from two decades ago. That’s because the error-handling model of HTML has always been to simply ignore any tags it doesn’t recognise and render the content inside them.

That pattern of behaviour is a direct result of the design principle:

Degrade Gracefully

…document conformance requirements should be designed so that Web content can degrade gracefully in older or less capable user agents, even when making use of new elements, attributes, APIs and content models.

Here’s a picture from 2006.

Tantek Çelik, Brian Suda, Ryan King, Chris Messina, Mark Norman Francis, and Jeremy Keith.

That’s me in the cowboy hat—the picture was taken in Austin, Texas. This is an impromptu gathering of people involved in the microformats community.

Microformats, like any other standards, are sets of agreements. In this case, they’re agreements on which class values to use to mark up some of the missing elements from HTML—people, places, and events. That’s pretty much it.

And yes, they do have design principles—some very good ones—but that’s not why I’m showing this picture.

Some of the people in this picture—Tantek Çelik, Ryan King, and Chris Messina—were involved in the creation of BarCamp, a series of grassroots geek gatherings.

BarCamps sound like they shouldn’t work, but they do. The schedule for the event is arrived at collectively at the beginning of the gathering. It’s kind of amazing how the agreement emerges—rough consensus and running events.

In the run-up to a BarCamp in 2007, Chris Messina posted this message to the fledgeling social networking site, twitter.com:

how do you feel about using # (pound) for groups. As in #barcamp [msg]?

This was when tagging was all the rage. We were all about folksonomies back then. Chris proposed that we would call this a “hashtag”.

I wasn’t a fan:

Thinking that hashtags disrupt the reading flow of natural language. Sorry @factoryjoe

But it didn’t matter what I thought. People agreed to this convention, and after a while Twitter began turning the hashtagged words into links.

In doing so, they were following another HTML design principle:

Pave the cowpaths

It sounds like advice for agrarian architects, but its meaning is clarified:

When a practice is already widespread among authors, consider adopting it rather than forbidding it or inventing something new.

Twitter had previously paved a cowpath when people started prefacing usernames with the @ symbol. That convention didn’t come from Twitter, but they didn’t try to stop it. They rolled with it, and turned any username prefaced with an @ symbol into a link.

The aperand symbol.

The @ symbol made sense because people were used to using it from email. The choice to use that symbol in email addresses was made by Ray Tomlinson. He needed a symbol to separate the person and the domain, looked down at his keyboard, saw the @ symbol, and thought “that’ll do.”

Perhaps Chris followed a similar process when he proposed the symbol for the hashtag.

The octothorpe symbol.

It could have just as easily been called a “number tag” or “octothorpe tag” or “pound tag”.

This symbol started life as a shortcut for “pound”, or more specifically “libra pondo”, meaning a pound in weight. Libra pondo was abbreviated to lb when written. That got turned into a ligature ℔ when written hastily. That shape was the common ancestor of two symbols we use today: £ and #.

The eight-pointed symbol was (perhaps jokingly) renamed the octothorpe in the 1960s when it was added to telephone keypads. It’s still there on the digital keypad of your mobile phone. If you were to ask someone born in this millenium what that key is called, they would probably tell you it’s the hashtag key. And if they’re learning to read sheet music, I’ve heard tell that they refer to the sharp notes as hashtag notes.

If this upsets you, you might be the kind of person who rages at the word “literally” being used to mean “figuratively” or supermarkets with aisles for “10 items or less” instead of “10 items or fewer”.

Tough luck. The English language is agreement. That’s why English dictionaries exist not to dictate usage of the language, but to document usage.

It’s much the same with web standards bodies. They don’t carve the standards into tablets of stone and then come down the mountain to distribute them amongst the browsers. No, it’s what the browsers implement that gets carved in stone. That’s why it’s so important that browsers are in agreement. In the bad old days of the browser wars of the late 90s, we saw what happened when browsers implemented their own proprietary features.

Standards require interoperability.

Interoperability requires agreement.

Standards atop Interoperability atop Agreement.

So what we can learn from the history of standardisation?

Well, there are some direct lessons from the HTML design principles.

The priority of constituencies

Consider users over authors…

Listen, I want developer convenience as much as the next developer. But never at the expense of user needs.

I’ve often said that if I have the choice between making something my problem, and making it the user’s problem, I’ll make it my problem every time. That’s the job.

I worry that these days developer convenience is sometimes prized more highly than user needs. I think we could all use a priority of constituencies on every project we work on, and I would hope that we would prioritise users over authors.

Degrade gracefully

Web content can degrade gracefully in older or less capable user agents…

I know that I go on about progressive enhancement a lot. Sometimes I make it sound like a silver bullet. Well, it kinda is.

I mean, you can’t just buy a bullet made of silver—you have to make it yourself. If you’re not used to crafting bullets from silver, it will take some getting used to.

Again, if developer convenience is your priority, silver bullets are hard to justify. But if you’re prioritising users over authors, progressive enhancement is the logical methodology to use.

Evolution, not revolution

It’s a testament to the power and flexibility of the web that we don’t have to build with progressive enhancement. We don’t have to build with a separation of concerns like structure, presentation, and behaviour.

We don’t have to use what the browser gives us: buttons, dropdowns, hyperlinks. If we want to, we can make these things from scratch using JavaScript, divs and ARIA attributes.

But why do that? Is it because those native buttons and dropdowns might be inconsistent from browser to browser.

Consistency is not the purpose of the world wide web.

Universality is the key principle underlying the web.

Our patterns should reflect the intent of the medium.

Use what the browser gives you—build on top of those agreements. Because that’s the bigger lesson to be learned from the history of web standards, clocks, containers, and hashtags.

Future atop Present atop Past.

Our world is made up of incremental improvements to what has come before. And that’s how we will push forward to a better tomorrow: By building on top of what we already have instead of trying to create something entirely from scratch. And by working together to get agreement instead of going it alone.

The future can be a frightening prospect, and I often get people asking me for advice on how they should prepare for the web’s future. Usually they’re thinking about which programming language or framework or library they should be investing their time in. But these specific patterns matter much less than the broader principles of working together, collaborating and coming to agreement. It’s kind of insulting that we refer to these as “soft skills”—they couldn’t be more important.

Working on the web, it’s easy to get downhearted by the seemingly ephemeral nature of what we build. None of it is “real”; none of it is tangible. And yet, looking at the history of civilisation, it’s the intangibles that survive: ideas, philosophies, culture and concepts.

The future can be frightening because it is intangible and unknown. But like all the intangible pieces of our consensus reality, the future is something we construct …through agreement.

Now let’s agree to go forward together to build the future web!

Wednesday, September 5th, 2018

Daring Fireball: Medium Deprecates Custom Domains Service

I know many people love Medium’s editing interface, but I just can’t believe that so many writers and publications have turned toward a single centralized commercial entity as a proposed solution to what ails the publishing industry. There is tremendous strength in independence and decentralization.

Sunday, September 2nd, 2018


I finally got around to reading Sapiens by Yuval Noah Harari. It’s one of those books that I kept hearing about from smart people whose opinions I respect. But I have to say, my reaction to the book reminded me of when I read Matt Ridley’s The Rational Optimist:

It was an exasperating read.

At first, I found the book to be a rollicking good read. It told the sweep of history in an engaging way, backed up with footnotes and references to prime sources. But then the author transitions from relaying facts to taking flights of fancy without making any distinction between the two (the only “tell” is that the references dry up).

Just as Matt Ridley had personal bugbears that interrupted the flow of The Rational Optimist, Yuval Noah Harari has fixated on some ideas that make a mess of the narrative arc of Sapiens. In particular, he believes that the agricultural revolution was, as he describes it, “history’s biggest fraud.” In the absence of any recorded evidence for this, he instead provides idyllic descriptions of the hunter-gatherer lifestyle that have as much foundation in reality as the paleo diet.

When the book avoids that particular historical conspiracy theory, it fares better. But even then, the author seems to think he’s providing genuinely new insights into matters of religion, economics, and purpose, when in fact, he’s repeating the kind of “college thoughts” that have been voiced by anyone who’s ever smoked a spliff.

I know I’m making it sound terrible, and it’s not terrible. It’s just …generally not that great. And when it is great, it only makes the other parts all the more frustrating. There’s a really good book in Sapiens, but unfortunately it’s interspersed with some pretty bad editorialising. I have to agree with Galen Strawson’s review:

Much of Sapiens is extremely interesting, and it is often well expressed. As one reads on, however, the attractive features of the book are overwhelmed by carelessness, exaggeration and sensationalism.

Towards the end of Sapiens, Yuval Noah Harari casts his eye on our present-day world and starts to speculate on the future. This is the point when I almost gave myself an injury with the amount of eye-rolling I was doing. His ideas on technology, computers, and even science fiction are embarrassingly childish and incomplete. And the bad news is that his subsequent books—Home Deus and 21 Lessons For The 21st Century—are entirely speculations about humanity and technology. I won’t be touching those with all the ten foot barge poles in the world.

In short, although there is much to enjoy in Sapiens, particularly in the first few chapters, I can’t recommend it.

If you’re looking for a really good book on the fascinating history of our species, read A Brief History of Everyone Who Ever Lived by Adam Rutherford . That’s one I can recommend without reservation.

Friday, August 10th, 2018


Over on A List Apart, you can read the first chapter from Tim’s new book, Flexible Typesetting.

I was lucky enough to get an advance preview copy and this book is ticking all my boxes. I mean, I knew I would love all the type nerdery in the book, but there’s a bigger picture too. In chapter two, Tim makes this provacative statement:

Typography is now optional. That means it’s okay for people to opt out.

That’s an uncomfortable truth for designers and developers, but it gets to the heart of what makes the web so great:

Of course typography is valuable. Typography may now be optional, but that doesn’t mean it’s worthless. Typographic choices contribute to a text’s meaning. But on the web, text itself (including its structural markup) matters most, and presentational instructions like typography take a back seat. Text loads first; typography comes later. Readers are free to ignore typographic suggestions, and often prefer to. Services like Instapaper, Pocket, and Safari’s Reader View are popular partly because readers like their text the way they like it.

What Tim describes there isn’t a cause for frustration or despair—it’s a cause for celebration. When we try to treat the web as a fixed medium where we can dictate the terms that people must abide by, we’re doing them (and the web) a disservice. Instead of treating web design as a pre-made contract drawn up by the designer and presented to the user as a fait accompli, it is more materially honest to treat web design as a conversation between designer and user. Both parties should have a say.

Or as Tim so perfectly puts it in Flexible Typesetting:

Readers are typographers, too.

Tuesday, August 7th, 2018

Console methods

Whenever I create a fetch event inside a service worker, my code roughly follows the same pattern. There’s a then clause which gets executed if the fetch is successful, and a catch clause in case anything goes wrong:

fetch( request)
.then( fetchResponse => {
    // Yay! It worked.
.catch( fetchError => {
    // Boo! It failed.

In my book—Going Offline—I’m at pains to point out that those arguments being passed into each clause are yours to name. In this example I’ve called them fetchResponse and fetchError but you can call them anything you want.

I always do something with the fetchResponse inside the then clause—either I want to return the response or put it in a cache.

But I rarely do anything with fetchError. Because of that, I’ve sometimes made the mistake of leaving it out completely:

fetch( request)
.then( fetchResponse => {
    // Yay! It worked.
.catch( () => {
    // Boo! It failed.

Don’t do that. I think there’s some talk of making the error argument optional, but for now, some browsers will get upset if it’s not there.

So always include that argument, whether you call it fetchError or anything else. And seeing as it’s an error, this might be a legitimate case for outputing it to the browser’s console, even in production code.

And yes, you can output to the console from a service worker. Even though a service worker can’t access anything relating to the document object, you can still make use of window.console, known to its friends as console for short.

My muscle memory when it comes to sending something to the console is to use console.log:

fetch( request)
.then( fetchResponse => {
    return fetchResponse;
.catch( fetchError => {

But in this case, the console.error method is more appropriate:

fetch( request)
.then( fetchResponse => {
    return fetchResponse;
.catch( fetchError => {

Now when there’s a connectivity problem, anyone with a console window open will see the error displayed bold and red.

If that seems a bit strident to you, there’s always console.warn which will still make the output stand out, but without being quite so alarmist:

fetch( request)
.then( fetchResponse => {
    return fetchResponse;
.catch( fetchError => {

That said, in this case, console.error feels like the right choice. After all, it is technically an error.

Friday, August 3rd, 2018

Greater expectations

I got an intriguing email recently from someone who’s a member of The Session, the community website about Irish traditional music that I run. They said:

When I recently joined, I used my tablet to join. Somewhere I was able to download The Session app onto my tablet.

But there is no native app for The Session. Although, as it’s a site that I built, it is, a of course, progressive web app.

They went on to say:

I wanted to put the app on my phone but I can’t find the app to download it. Can I have the app on more than one device? If so, where is it available?

I replied saying that yes, you can absolutely have it on more than one device:

But you don’t find The Session app in the app store. Instead you go to the website https://thesession.org and then add it to your home screen from your browser.

My guess is that this person had added The Session to the home screen of their Android tablet, probably following the “add to home screen” prompt. I recently added some code to use the window.beforeinstallprompt event so that the “add to home screen” prompt would only be shown to visitors who sign up or log in to The Session—a good indicator of engagement, I reckon, and it should reduce the chance of the prompt being dismissed out of hand.

So this person added The Session to their home screen—probably as a result of being prompted—and then used it just like any other app. At some point, they didn’t even remember how the app got installed:

Success! I did it. Thanks. My problem was I was looking for an app to download.

On the one hand, this is kind of great: here’s an example where, in the user’s mind, there’s literally no difference between the experience of using a progressive web app and using a native app. Win!

But on the other hand, the expectation is still that apps are to be found in an app store, not on the web. This expectation is something I wrote about recently (and Justin wrote a response to that post). I finished by saying:

Perhaps the inertia we think we’re battling against isn’t such a problem as long as we give people a fast, reliable, engaging experience.

When this member of The Session said “My problem was I was looking for an app to download”, I responded by saying:

Well, I take that as a compliment—the fact that once the site is added to your home screen, it feels just like a native app. :-)

And they said:

Yes, it does!

Thursday, August 2nd, 2018


Chris has written about switching code editors. I’m a real stick-in-the-mud when it comes to switching editors. Partly that’s because I’m generally pretty happy with whatever I’m using (right now it’s Atom) but it’s also because I just don’t get that excited about software like this. I probably should care more; I spend plenty of time inside a code editor. And I should really take the time to get to grips with features like keyboard shortcuts—I’m sure I’m working very inefficiently. But, like I said, I find it hard to care enough, and on the whole, I’m content.

I was struck by this observation from Chris:

When moving, I have to take time to make sure it works pretty much like the old one.

That reminded me of a recent switch I made, not with code editors, but with browsers.

I’ve been using Chrome for years. One day it started crashing a lot. So I decided to make the switch to Firefox. Looking back, I’m glad to have had this prompt—I think it’s good to shake things up every now and then, so I don’t get too complacent (says the hypocrite who can’t be bothered to try a new code editor).

Just as Chris noticed with code editors, it was really important that I could move bookmarks (and bookmarklets!) over to my new browser. On the whole, it went pretty smoothly. I had to seek out a few browser extensions but that was pretty much it. And because I use a password manager, logging into all my usual services wasn’t a hassle.

Of all the pieces of software on my computer, the web browser is the one where I definitely spend the most time: reading, linking, publishing. At this point, I’m very used to life with Firefox as my main browser. It’s speedy and stable, and the dev tools are very similar to Chrome’s.

Maybe I’ll switch to Safari at some point. Like I said, I think it’s good to shake things up and get out of my comfort zone.

Now, if I really wanted to get out of my comfort zone, I’d switch operating systems like Dave did with his move to Windows. And I should really try using a different phone OS. Again, this is something that Dave tried with his switch to Android (although that turned out to be unacceptably creepy), and Paul did it ages ago using a Windows phone for a week.

There’s probably a balance to be struck here. I think it’s good to change code editors, browsers, even operating systems and phones every now and then, but I don’t want to feel like I’m constantly in learning mode. There’s something to be said for using tools that are comfortable and familiar, even if they’re outdated.

Wednesday, July 25th, 2018

The history of design systems at Clearleft

Danielle has posted a brief update on Fractal:

We decided to ask the Fractal community for help, and the response has been overwhelming. We’ve received so many offers of support in all forms that we can safely say that development will be starting up again shortly.

It’s so gratifying to see that other people are finding Fractal to be as useful to them as it is to us. We very much appreciate all their support!

Although Fractal itself is barely two years old, it’s part of a much longer legacy at Clearleft

It all started with Natalie. She gave a presentation back in 2009 called Practical Maintainable CSS . She talks about something called a pattern porfolio—a deliverable that expresses every component and documents how the markup and CSS should be used.

When Anna was interning at Clearleft, she was paired up with Natalie so she was being exposed to these ideas. She then expanded on them, talking about Front-end Style Guides. She literally wrote the book on the topic, and starting curating the fantastic collection of examples at styleguides.io.

When Paul joined Clearleft, it was a perfect fit. He was already obsessed with style guides (like the BBC’s Global Experience Language) and started writing and talking about styleguides for the web:

At Clearleft, rather than deliver an inflexible set of static pages, we present our code as a series of modular components (a ‘pattern portfolio’) that can be assembled into different configurations and page layouts as required.

Such systematic thinking was instigated by Natalie, yet this is something we continually iterate upon.

To see the evolution of Paul’s thinking, you can read his three part series from last year on designing systems:

  1. Theory, Practice, and the Unfortunate In-between,
  2. Layers of Longevity, and
  3. Components and Composition

Later, Charlotte joined Clearleft as a junior developer, and up until that point, hadn’t been exposed to the idea of pattern libraries or design systems. But it soon became clear that she had found her calling. She wrote a brilliant article for A List Apart called From Pages to Patterns: An Exercise for Everyone and she started speaking about design systems at conferences like Beyond Tellerrand. Here, she acknowledges the changing terminology over the years:

Pattern portfolio is a term used by Natalie Downe when she started using the technique at Clearleft back in 2009.

Front-end style guides is another term I’ve heard a lot.

Personally, I don’t think it matters what you call your system as long as it’s appropriate to the project and everyone uses it. Today I’m going to use the term “pattern library”.

(Mark was always a fan of the term “component library”.)

Now Charlotte is a product manager at Ansarada in Sydney and the product she manages is …the design system!

Thinking back to my work on starting design systems, I didn’t realise straight away that I was working on a product. Yet, the questions we ask are similar to those we ask of any product when we start out. We make decisions on things like: design, architecture, tooling, user experience, code, releases, consumption, communication, and more.

It’s been fascinating to watch the evolution of design systems at Clearleft, accompanied by an evolution in language: pattern portfolios; front-end style guides; pattern libraries; design systems.

There’s been a corresponding evolution in prioritisation. Where Natalie was using pattern portfolios as a deliverable for handover, Danielle is now involved in the integration of design systems within a client’s team. The focus on efficiency and consistency that Natalie began is now expressed in terms of design ops—creating living systems that everyone is involved in.

When I step back and look at the history of design systems on the web, there are some obvious names that have really driven their evolution and adoption, like Jina Anne, Brad Frost, and Alla Kholmatova. But I’m amazed at the amount of people who have been through Clearleft’s doors that have contributed so, so much to this field:

Natalie Downe, Anna Debenham, Paul Lloyd, Mark Perkins, Charlotte Jackson, and Danielle Huntrods …thank you all!

Tuesday, July 24th, 2018

Altering expectations

Luke has written up the selection process he went through when Clearleft was designing the Virgin Holidays app. When it comes to deploying on mobile, there were three options:

  1. Native apps
  2. A progressive web app
  3. A hybrid app

The Virgin Holidays team went with that third option.

Now, it will come as no surprise that I’m a big fan of the second option: building a progressive web app (or turning an existing site into a progressive web app). I think a progressive web app is a great solution for travel apps, and the use-case that Luke describes sounds perfect:

Easy access to resort staff and holiday details that could be viewed offline to help as many customers as possible travel without stress and enjoy a fantastic holiday

Luke explains why they choice not to go with a progressive web app.

The current level of support and leap in understanding meant we’d risk alienating many of our customers.

The issue of support is one that is largely fixed at this point. When Clearleft was working on the Virgin Holidays app, service workers hadn’t landed in iOS. Hence, the risk of alienating a lot of customers. But now that Mobile Safari has offline capabilities, that’s no longer a problem.

But it’s the second reason that’s trickier:

Simply put, customers already expected to find us in the App Store and are familiar with what apps can historically offer over websites.

I think this is the biggest challenge facing progressive web apps: battling expectations.

For over a decade, people have formed ideas about what to expect from the web and what to expect from native. From a technical perspective, native and web have become closer and closer in capabilities. But people’s expectations move slower than technological changes.

First of all, there’s the whole issue of discovery: will people understand that they can “install” a website and expect it to behave exactly like a native app? This is where install prompts and ambient badging come in. I think ambient badging is the way to go, but it’s still a tricky concept to explain to people.

But there’s another way of looking at the current situation. Instead of seeing people’s expectations as a negative factor, maybe it’s an opportunity. There’s an opportunity right now for companies to be as groundbreaking and trendsetting as Wired.com when it switched to CSS for layout, or The Boston Globe when it launched its responsive site.

It makes for a great story. Just look at the Pinterest progressive web app for an example (skip to the end to get to the numbers):

Weekly active users on mobile web have increased 103 percent year-over-year overall, with a 156 percent increase in Brazil and 312 percent increase in India. On the engagement side, session length increased by 296 percent, the number of Pins seen increased by 401 percent and people were 295 percent more likely to save a Pin to a board. Those are amazing in and of themselves, but the growth front is where things really shined. Logins increased by 370 percent and new signups increased by 843 percent year-over-year. Since we shipped the new experience, mobile web has become the top platform for new signups. And for fun, in less than 6 months since fully shipping, we already have 800 thousand weekly users using our PWA like a native app (from their homescreen).

Now admittedly their previous mobile web experience was a dreadful doorslam, but still, those are some amazing statistics!

Maybe we’re underestimating the malleability of people’s expectations when it comes to the web on mobile. Perhaps the inertia we think we’re battling against isn’t such a problem as long as we give people a fast, reliable, engaging experience.

If you build that, they will come.

Friday, July 13th, 2018

CSS grid in Internet Explorer 11

When I was in Boston, speaking on a lunchtime panel with Rachel at An Event Apart, we took some questions from the audience about CSS grid. Inevitably, a question about browser support came up—specifically about support in Internet Explorer 11.

(Technically, you can use CSS grid in IE11—in fact it was the first browser to ship a version of grid—but the prefixed syntax is different to the standard and certain features are missing.)

Rachel gave a great balanced response, saying that you need to look at your site’s stats to determine whether it’s worth the investment of your time trying to make a grid work in IE11.

My response was blunter. I said I just don’t consider IE11 as a browser that supports grid.

Now, that might sound harsh, but what I meant was: you’re already dividing your visitors into browsers that support grid, and browsers that don’t …and you’re giving something to those browsers that don’t support grid. So I’m suggesting that IE11 falls into that category and should receive the layout you’re giving to browsers that don’t support grid …because really, IE11 doesn’t support grid: that’s the whole reason why the syntax is namespaced by -ms.

You could jump through hoops to try to get your grid layout working in IE11, as detailed in a three-part series on CSS Tricks, but at that point, the amount of effort you’re putting in negates the time-saving benefits of using CSS grid in the first place.

Frankly, the whole point of prefixed CSS is that is not used after a reasonable amount of time (originally, the idea was that it would not be used in production, but that didn’t last long). As we’ve moved away from prefixes to flags in browsers, I’m seeing the amount of prefixed properties dropping, and that’s very, very good. I’ve stopped using autoprefixer on new projects, and I’ve been able to remove it from some existing ones—please consider doing the same.

And when it comes to IE11, I’ll continue to categorise it as a browser that doesn’t support CSS grid. That doesn’t mean I’m abandoning users of IE11—far from it. It means I’m giving them the layout that’s appropriate for the browser they’re using.

Remember, websites do not need to look exactly the same in every browser.

Wednesday, July 11th, 2018

Links, tags, and feeds

A little while back, I switched from using Chrome as my day-to-day browser to using Firefox. I could feel myself getting a bit too comfortable with one particular browser, and that’s not good. I reckon it’s good to shake things up a little every now and then. Besides, there really isn’t that much difference once you’ve transferred over bookmarks and cookies.

Unfortunately I’m being bitten by this little bug in Firefox. It causes some of my bookmarklets to fail on certain sites with strict Content Security Policies (and CSPs shouldn’t affect bookmarklets). I might have to switch back to Chrome because of this.

I use bookmarklets throughout the day. There’s the Huffduffer bookmarklet, of course, for whenever I come across a podcast episode or other piece of audio that I want to listen to later. But there’s also my own home-rolled bookmarklet for posting links to my site. It doesn’t do anything clever—it grabs the title and URL of the currently open page and pre-populates a form in a new window, leaving me to add a short description and some tags.

If you’re reading this, then you’re familiar with the “journal” section of adactio.com, but the “links” section is where I post the most. Here, for example, are all the links I posted yesterday. It varies from day to day, but there’s generally a handful.

Should you wish to keep track of everything I’m linking to, there’s a twitterbot you can follow called @adactioLinks. It uses a simple IFTTT recipe to poll my RSS feed of links and send out a tweet whenever there’s a new entry.

Or you can drink straight from the source and subscribe to the RSS feed itself, if you’re still rocking it old-school. But if RSS is your bag, then you might appreciate a way to filter those links…

All my links are tagged. Heavily. This is because all my links are “notes to future self”, and all my future self has to do is ask “what would past me have tagged that link with?” when I’m trying to find something I previously linked to. I end up using my site’s URLs as an interface:

At the front-end gatherings at Clearleft, I usually wrap up with a quick tour of whatever I’ve added that week to:

Well, each one of those tags also has a corresponding RSS feed:

…and so on.

That means you can subscribe to just the links tagged with something you’re interested in. Here’s the full list of tags if you’re interested in seeing the inside of my head.

This also works for my journal entries. If you’re only interested in my blog posts about frontend development, you might want to subscribe to:

Here are all the tags from my journal.

You can even mix them up. For everything I’ve tagged with “typography”—whether it’s links, journal entries, or articles—the URL is:

The corresponding RSS feed is:

You get the idea. Basically, if something on my site is a list of items, chances are there’s a corresponding RSS feeds. Sometimes there might even be a JSON feed. Hack some URLs to see.

Meanwhile, I’ll be linking, linking, linking…