Journal tags: browsers

94

sparkline

Apple’s attack on service workers

Apple aren’t the best at developer relations. But, bad as their communications can be, I’m willing to cut them some slack. After all, they’re not used to talking with the developer community.

John Wilander wrote a blog post that starts with some excellent news: Full Third-Party Cookie Blocking and More. Safari is catching up to Firefox and disabling third-party cookies by default. Wonderful! I’ve had third-party cookies disabled for a few years now, and while something occassionally breaks, it’s honestly a pretty great experience all around. Denying companies the ability to track users across sites is A Good Thing.

In the same blog post, John said that client-side cookies will be capped to a seven-day lifespan, as previously announced. Just to be clear, this only applies to client-side cookies. If you’re setting a cookie on the server, using PHP or some other server-side language, it won’t be affected. So persistent logins are still doable.

Then, in an audacious example of burying the lede, towards the end of the blog post, John announces that a whole bunch of other client-side storage technologies will also be capped to seven days. Most of the technologies are APIs that, like cookies, can be used to store data: Indexed DB, Local Storage, and Session Storage (though there’s no mention of the Cache API). At the bottom of the list is this:

Service Worker registrations

Okay, let’s clear up a few things here (because they have been so poorly communicated in the blog post)…

The seven day timer refers to seven days of Safari usage, not seven calendar days (although, given how often most people use their phones, the two are probably interchangable). So if someone returns to your site within a seven day period of using Safari, the timer resets to zero, and your service worker gets a stay of execution. Lucky you.

This only applies to Safari. So if your site has been added to the home screen and your web app manifest has a value for the “display” property like “standalone” or “full screen”, the seven day timer doesn’t apply.

That piece of information was missing from the initial blog post. Since the blog post was updated to include this clarification, some people have taken this to mean that progressive web apps aren’t affected by the upcoming change. Not true. Only progressive web apps that have been added to the home screen (and that have an appropriate “display” value) will be spared. That’s a vanishingly small percentage of progressive web apps, especially on iOS. To add a site to the home screen on iOS, you need to dig and scroll through the share menu to find the right option. And you need to do this unprompted. There is no ambient badging in Safari to indicate that a site is installable. Chrome’s install banner isn’t perfect, but it’s better than nothing.

Just a reminder: a progressive web app is a website that

  • runs on HTTPS,
  • has a service worker,
  • and a web manifest.

Adding to the home screen is something you can do with a progressive web app (or any other website). It is not what defines progressive web apps.

In any case, this move to delete service workers after seven days of using Safari is very odd, and I’m struggling to find the connection to the rest of the blog post, which is about technologies that can store data.

As I understand it, with the crackdown on setting third-party cookies, trackers are moving to first-party technologies. So whereas in the past, a tracking company could tell its customers “Add this script element to your pages”, now they have to say “Add this script element and this script file to your pages.” That JavaScript file can then store a unique idenitifer on the client. This could be done with a cookie, with Local Storage, or with Indexed DB, for example. But I’m struggling to understand how a service worker script could be used in this way. I’d really like to see some examples of this actually happening.

The best explanation I can come up with for this move by Apple is that it feels like the neatest solution. That’s neat as in tidy, not as in nifty. It is definitely not a nifty solution.

If some technologies set by a specific domain are being purged after seven days, then the tidy thing to do is purge all technologies from that domain. Service workers are getting included in that dragnet.

Now, to be fair, browsers and operating systems are free to clean up storage space as they see fit. Caches, Local Storage, Indexed DB—all of those are subject to eventually getting cleaned up.

So I was curious. Wanting to give Apple the benefit of the doubt, I set about trying to find out how long service worker registrations currently last before getting deleted. Maybe this announcement of a seven day time limit would turn out to be not such a big change from current behaviour. Maybe currently service workers last for 90 days, or 60, or just 30.

Nope:

There was no time limit previously.

This is not a minor change. This is a crippling attack on service workers, a technology specifically designed to improve the user experience for return visits, whether it’s through improved performance or offline access.

I wouldn’t be so stunned had this announcement come with an accompanying feature that would allow Safari users to know when a website is a progressive web app that can be added to the home screen. But Safari continues to ignore the existence of progressive web apps. And now it will actively discourage people from using service workers.

If you’d like to give feedback on this ludicrous development, you can file a bug (down in the cellar in the bottom of a locked filing cabinet stuck in a disused lavatory with a sign on the door saying “Beware of the Leopard”).

No doubt there will still be plenty of Apple apologists telling us why it’s good that Safari has wished service workers into the cornfield. But make no mistake. This is a terrible move by Apple.

I will say this though: given The Situation we’re all living in right now, some good ol’ fashioned Hot Drama by a browser vendor behaving badly feels almost comforting.

Lighthouse bookmarklet

I use Firefox. You should too. It’s fast, secure, and more privacy-focused than the leading browser from the big G.

When it comes to web development, the CSS developer tooling in Firefox is second-to-none. But when it comes to JavaScript and network-related debugging (like service workers), Chrome’s tools are currently better than Firefox’s (for now). For example, Chrome has a tab in its developer tools that lets you run Lighthouse on the currently open tab.

Yesterday, I got the Calibre newsletter, which always has handy performance-related links from Karolina. She pointed to a Lighthouse extension for Firefox. “Excellent!”, I thought, and I immediately installed it. But I had some qualms about installing a plug-in from Google into a browser from Mozilla, particularly as the plug-in page says:

This is not a Recommended Extension. Make sure you trust it before installing

Well, I gave it a go. It turns out that all it actually does is redirect to the online version of Lighthouse. “Hang on”, I thought. “This could just be a bookmarklet!”

So I immediately uninstalled the browser extension and made this bookmarklet:

Lighthouse

Drag that up to your desktop browser’s bookmarks toolbar. Press it whenever you’re on a site that you want to test.

Insecure

Universal access is at the heart of the World Wide Web. It’s also something I value when I’m building anything on the web. Whatever I’m building, I want you to be able to visit using whatever browser or device that you choose.

Just to be clear, that doesn’t mean that you’re going to have the same experience in an old browser as you are in the latest version of Firefox or Chrome. Far from it. Not only is that not feasible, I don’t believe it’s desirable either. But if you’re using an old browser, while you might not get to enjoy the newest CSS or JavaScript, you should still be able to access a website.

Applying the principle of progressive enhancement makes this emminently doable. As long as I build in a layered way, everyone gets access to the barebones HTML, even if they can’t experience newer features. Crucially, as long as I’m doing some feature detection, those newer features don’t harm older browsers.

But there’s one area where maintaining backward compatibility might well have an adverse effect on modern browsers: security.

I don’t just mean whether or not you’re serving sites over HTTPS. Even if you’re using TLS—Transport Layer Security—not all security is created equal.

Take a look at Mozilla’s very handy SSL Configuration Generator. You get to choose from three options:

  1. Modern. Services with clients that support TLS 1.3 and don’t need backward compatibility.
  2. Intermediate. General-purpose servers with a variety of clients, recommended for almost all systems.
  3. Old. Compatible with a number of very old clients, and should be used only as a last resort.

Because I value universal access, I should really go for the “old” setting. That ensures my site is accessible all the way back to Android 2.3 and Safari 1. But if I do that, I will be supporting TLS 1.0. That’s not good. My site is potentially vulnerable.

Alright then, I’ll go for “intermediate”—that’s the recommended level anyway. Now I’m no longer providing TLS 1.0 support. But that means some older browsers can no longer access my site.

This is exactly the situation I found myself in with The Session. I had a score of A+ from SSL Labs. I was feeling downright smug. Then I got emails from actual users. One had picked up an old Samsung tablet second hand. Another was using an older version of Safari. Neither could access the site.

Sure enough, if you cut off TLS 1.0, you cut off Safari below version six.

Alright, then. Can’t they just upgrade? Well …no. Apple has tied Safari to OS X. If you can’t upgrade your operating system, you can’t upgrade your browser. So if you’re using OS X Mountain Lion, you’re stuck with an insecure version of Safari.

Fortunately, you can use a different browser. It’s possible to install, say, Firefox 37 which supports TLS 1.2.

On desktop, that is. If you’re using an older iPhone or iPad and you can’t upgrade to a recent version of iOS, you’re screwed.

This isn’t an edge case. This is exactly the kind of usage that iPads excel at: you got the device a few years back just to do some web browsing and not much else. It still seems to work fine, and you have no incentive to buy a brand new iPad. And nor should you have to.

In that situation, you’re stuck using an insecure browser.

As a site owner, I can either make security my top priority, which means you’ll no longer be able to access my site. Or I can provide you access, which makes my site less secure for everyone. (That’s what I’ve done on The Session and now my score is capped at B.)

What I can’t do is tell you to install a different browser, because you literally can’t. Sure, technically you can install something called Firefox from the App Store, or you can install something called Chrome. But neither have anything to do with their desktop counterparts. They’re differently skinned versions of Safari.

Apple refuses to allow browsers with any other rendering engine to be installed. Their reasoning?

Security.

IncrementURL

Last month I wrote some musings on default browser behaviours. When it comes to all the tasks that browsers do for us, the most fundamental is taking a URL, fetching its contents and giving us the results. As part of that process, browsers also show us the URL of the page currently loaded in a tab or window.

But even at this fundamental level, there are some differences from browser to browser.

Safari only shows you the domain name—and any subdomain names—by default. It looks like nice and tidy, but it obfuscates what page you’re on (until you click on the domain name). This is bad.

Chrome shows you the full URL, nice and straightforward. This is neutral.

Firefox, like Chrome, shows you the full URL, but with a subtle difference. The important part of the URL—usually the domain name—is subtly highlighted in a darker shade of grey. This is good.

The reason I say that what it highlights is usually the domain name is because what it actually highlights is eTLD+1.

The what now?

Well, if you’re looking at a page on adactio.com, that’s the important bit. But what if you’re looking at a page on adactio.github.io? The domain name is important, but so is the subdomain.

It turns out there’s a list out there of which sites and top level domains allow registrations like this. This is the list that Firefox is using for its shading behaviour in displaying URLs.

Safari, by the way, does not use this list. These URLs are displayed identically in Safari, the phisherman’s friend:

  • example.com
  • example.github.io
  • github.example.com

Whereas Firefox displays them as:

  • example.com
  • example.github.io
  • github.example.com

I learned all this from Jake on a recent edition of HTTP 203. Nicolas Hoizey has writen a nice little summary.

Jake acknowledges that what Apple is doing is shisuboptimal, what Firefox is doing is good, and then puts forward an idea for what Chrome could do. (But please note that this is Jake’s personal opinion; not an official proposal from the Chrome team.)

There’s some prior art here. It used to be that, if your SSL certificate included extended validation, the name would be shown in green next to the padlock symbol. So while my website—which uses regular SSL from Let’s Encrypt—would just have a padlock, Medium—which uses EV SSL—would have a padlock and the text “A Medium Corporation”.

Extended validation wasn’t quite the bulletproof verification it was cracked up to be. So browsers don’t use that interface pattern any more.

Jake suggests repurposing this pattern for all URLs. Pull out the important bit—eTLD+1—and show it next to the padlock.

Screenshots of @JaffaTheCake’s idea for separating out the eTLD+1 part of a URL in a browser’s address bar. Screenshots of @JaffaTheCake’s idea for separating out the eTLD+1 part of a URL in a browser’s address bar.

I like this. The full URL is still displayed. This proposal is more of an incremental change. An enhancement that is applied progressively, if you will.

I also like that it builds on existing interface patterns—Firefox’s URL treatment and the deprecated treatment of EV certs. In fact, I think the first step for Chrome should be to match Firefox’s current behaviour, and then go further with something like Jake’s proposal.

This kind of gradual change was exactly what Chrome did with displaying https and http domains.

Chrome treatment for HTTPS pages.

Jake mentions this in the video

We’ve already seen that you have to take small steps here, like we did with the https change.

There’s a fascinating episode of the Freakonomics podcast called In Praise of Incrementalism. I’ve huffduffed it.

I’m a great believer in the HTML design principle, Evolution Not Revolution:

It is better to evolve an existing design rather than throwing it away.

I’d love to see Chrome take the first steps to Jake’s proposal by following Firefox’s lead.

Then again, I’d love it if Chrome followed Firefox’s lead in implementing subgrid.

Unity

It’s official. Microsoft’s Edge browser is running on the Blink rendering engine and it’s available now.

Just over a year ago, I wrote about my feelings on this decision:

I’m sure the decision makes sound business sense for Microsoft, but it’s not good for the health of the web.

The importance of browser engine diversity is beautifully illustrated (literally) in Rachel’s The Ecological Impact of Browser Diversity.

But I was chatting to Amber the other day, and I mentioned how I can see the theoretical justification for Microsoft’s decision …even if I don’t quite buy it myself.

Picture, if you will, something I’ll call the bar of unity. It’s a measurement of how much collaboration is happening between browser makers.

In the early days of the web, the bar of unity was very low indeed. The two main browser vendors—Microsoft and Netscape—not only weren’t collaborating, they were actively splintering the languages of the web. One of them would invent a new HTML element, and the other would invent a completely different element to do the same thing (remember abbr and acronym). One of them would come up with one model for interacting with a document through JavaScript, and the other would come up with a completely different model to the same thing (remember document.all and document.layers).

There wasn’t enough collaboration. Our collective anger at this situation led directly to the creation of The Web Standards Project.

Eventually, those companies did start collaborating on standards at the W3C. The bar of unity was raised.

This has been the situation for most of the web’s history. Different browser makers agreed on standards, but went their own separate ways on implementation. That’s where they drew the line.

Now that line is being redrawn. The bar of unity is being raised. Now, a number of separate browser makers—Google, Samsung, Microsoft—not only collaborate on standards but also on implementation, sharing a codebase.

The bar of unity isn’t right at the top. Browsers can still differentiate in their user interfaces. Edge, for example, can—and does—offer very sensible defaults for blocking trackers. That’s much harder for Chrome to do, given that Google are amongst the worst offenders.

So these browsers are still competing, but the competition is no longer happening at the level of the rendering engine.

I can see how this looks like a positive development. In fact, from this point of view, Mozilla are getting in the way of progress by having a separate codebase (yes, this is a genuinely-held opinion by some people).

On the face of it, more unity sounds good. It sounds like more collaboration. More cooperation.

But then I think of situations where complete unity isn’t necessarily a good thing. Take political systems, for example. If you have hundreds of different political parties, that’s not ideal. But if you only have one political party, that’s very bad indeed!

There’s a sweet spot somewhere in between where there’s a base of level of agreement and cooperation, but there’s also plenty of room for disagreement and opposition. Right now, the browser landscape is just about still in that sweet spot. It’s like a two-party system where one party has a crushing majority. Checks and balances exist, but they’re in peril.

Firefox is one of the last remaining representatives offering an alternative. The least we can do is support it.

Install prompt

There’s an interesting thread on Github about the tongue-twistingly named beforeinstallpromt JavaScript event.

Let me back up…

Progressive web apps. You know what they are, right? They’re websites that have taken their vitamins. Specifically, they’re responsive websites that:

  1. are served over HTTPS,
  2. have a web app manifest, and
  3. have a service worker handling the offline scenario.

The web app manifest—a JSON file of metadata—is particularly useful for describing how your site should behave if someone adds it to their home screen. You can specify what icon should be used. You can specify whether the site should launch in a browser or as a standalone app (practically indistinguishable from a native app). You can specify which URL on the site should be used as the starting point when the site is launched from the home screen.

So progressive web apps work just fine when you visit them in a browser, but they really shine when you add them to your home screen. It seems like pretty much everyone is in agreement that adding a progressive web app to your home screen shouldn’t be an onerous task. But how does the browser let the user know that it might be a good idea to “install” the web site they’re looking at?

The Samsung Internet browser does ambient badging—a + symbol shows up to indicate that a website can be installed. This is a great approach!

I hope that Chrome on Android will also use ambient badging at some point. To start with though, Chrome notified users that a site was installable by popping up a notification at the bottom of the screen. I think these might be called “toasts”.

Getting the “add to home screen” prompt for https://huffduffer.com/ on Android Chrome. And there’s the “add to home screen” prompt for https://html5forwebdesigners.com/ HTTPS + manifest.json + Service Worker = “Add to Home Screen” prompt. Add to home screen.

Needless to say, the toast notification wasn’t very effective. That’s because we web designers and developers have spent years teaching people to immediately dismiss those notifications without even reading them. Accept our cookies! Sign up to our newsletter! Install our native app! Just about anything that’s user-hostile gets put in a notification (either a toast or an overlay) and shoved straight in the user’s face before they’ve even had time to start reading the content they came for in the first place. Users will then either:

  1. turn around and leave, or
  2. use muscle memory reach for that X in the corner of the notification.

A tiny fraction of users might actually click on the call to action, possibly by mistake.

Chrome didn’t abandon the toast notification for progressive web apps, but it did change when they would appear. Rather than the browser deciding when to show the prompt—usually when the user has just arrived on the site—a new JavaScript event called beforeinstallprompt can be used.

It’s a bit weird though. You have to “capture” the event that fires when the prompt would have normally been shown, subdue it, hold on to that event, and then re-release it when you think it should be shown (like when the user has completed a transaction, for example, and having your site on the home screen would genuinely be useful). That’s a lot of hoops. Here’s the code I use on The Session to only show the installation prompt to users who are logged in.

The end result is that the user is still shown a toast notification, but at least this time it’s the site owner who has decided when it will be shown. The Chrome team call this notification “the mini-info bar”, and Pete acknowledges that it’s not ideal:

The mini-infobar is an interim experience for Chrome on Android as we work towards creating a consistent experience across all platforms that includes an install button into the omnibox.

I think “an install button in the omnibox” means ambient badging in the browser interface, which would be great!

Anyway, back to that thread on Github. Basically, neither Apple nor Mozilla are going to implement the beforeinstallprompt event (well, technically Mozilla have implemented it but they’re not going to ship it). That’s fair enough. It’s an interim solution that’s not ideal for all reasons I’ve already covered.

But there’s a lot of pushback. Even if the details of beforeinstallprompt are troublesome, surely there should be some way for site owners to let users know that can—or should—install a progressive web app? As a site owner, I have a lot of sympathy for that viewpoint. But I also understand the security and usability issues that can arise from bad actors abusing this mechanism.

Still, I have to hand it to Chrome: even if we put the beforeinstallprompt event to one side, the browser still has a mechanism for letting users know that a progressive web app can be installed—the mini info bar. It’s not a great mechanism, but it’s better than nothing. Nothing is precisely what Firefox and Safari currently offer (though Firefox is experimenting with something).

In the case of Safari, not only do they not provide a mechanism for letting the user know that a site can be installed, but since the last iOS update, they’ve buried the “add to home screen” option even deeper in the “sharing sheet” (the list of options that comes up when you press the incomprehensible rectangle-with-arrow-emerging-from-it icon). You now have to scroll below the fold just to find the “add to home screen” option.

So while I totally get the misgivings about beforeinstallprompt, I feel that a constructive alternative wouldn’t go amiss.

And that’s all I have to say about that.

Except… there’s another interesting angle to that Github thread. There’s talk of allowing sites that are launched from the home screen to have access to more features than a site inside a web browser. Usually permissions on the web are explicitly granted or denied on a case-by-case basis: geolocation; notifications; camera access, etc. I think this is the first time I’ve heard of one action—adding to the home screen—being used as a proxy for implicitly granting more access. Very interesting. Although that idea seems to be roundly rejected here:

A key argument for using installation in this manner is that some APIs are simply so powerful that the drive-by web should not be able to ask for them. However, this document takes the position that installation alone as a restriction is undesirable.

Then again:

I understand that Chromium or Google may hold such a position but Apple’s WebKit team may not necessarily agree with such a position.

Browser defaults

I’ve been thinking about some of the default behaviours that are built into web browsers.

First off, there’s the decision that a browser makes if you enter a web address without a protocol. Let’s say you type in example.com without specifying whether you’re looking for http://example.com or https://example.com.

Browsers default to HTTP rather than HTTPS. Given that HTTP is older than HTTPS that makes sense. But given that there’s been such a push for TLS on the web, and the huge increase in sites served over HTTPS, I wonder if it’s time to reconsider that default?

Most websites that are served over HTTPS have an automatic redirect from HTTP to HTTPS (enforced with HSTS). There’s an ever so slight performance hit from that, at least for the very first visit. If, when no protocol is specified, browsers were to attempt to reach the HTTPS port first, we’d get a little bit of a speed improvement.

But would that break any existing behaviour? I don’t know. I guess there would be a bit of a performance hit in the other direction. That is, the browser would try HTTPS first, and when that doesn’t exist, go for HTTP. Sites served only over HTTP would suffer that little bit of lag.

Whatever the default behaviour, some sites are going to pay that performance penalty. Right now it’s being paid by sites that are served over HTTPS.

Here’s another browser default that Rob mentioned recently: the viewport meta tag:

I thought I might be able to get away with omitting meta name="viewport". Apparently not! Maybe someday.

This all goes back to the default behaviour of Mobile Safari when the iPhone was first released. Most sites wouldn’t display correctly if one pixel were treated as one pixel. That’s because most sites were built with the assumption that they would be viewed on monitors rather than phones. Only weirdos like me were building sites without that assumption.

So the default behaviour in Mobile Safari is assume a page width of 1024 pixels, and then shrink that down to fit on the screen …unless the developer over-rides that behaviour with a viewport meta tag. That default behaviour was adopted by other mobile browsers. I think it’s a universal default.

But the web has changed since the iPhone was released in 2007. Responsive design has swept the web. What would happen if mobile browsers were to assume width=device-width?

The viewport meta element always felt like a (proprietary) band-aid rather than a long-term solution—for one thing, it’s the kind of presentational information that belongs in CSS rather than HTML. It would be nice if we could bid it farewell.

Third party

The web turned 30 this year. When I was back at CERN to mark this anniversary, there was a lot of introspection and questioning the direction that the web has taken. Everyone I know that uses the web is in agreement that tracking and surveillance are out of control. It seems only right to question whether the web has lost its way.

But here’s the thing: the technologies that enable tracking and surveillance didn’t exist in the early years of the web—JavaScript and cookies.

Without cookies, the web was stateless. This was by design. Now, I totally understand why cookies—or something like cookies—were needed. Without some way of keeping track of state, there’s no good way for a website to “remember” what’s in your shopping cart, or whether you’ve authenticated yourself.

But why would cookies ever need to work across domains? Authentication, shopping carts and all that good stuff can happen on the same domain. Third-party cookies, on the other hand, seem custom made for tracking and frankly, not much else.

Browsers allow you to disable third-party cookies, though it’s not yet the default. If enough people do it—and complain about the sites that stop working when third-party cookies are disabled—then maybe it can become the default.

Firefox is taking steps in this direction, automatically disabling some third-party cookies—the ones that known trackers. Safari is also taking steps to prevent cross-site tracking. It’s not too late to change the tide of third-party cookies.

Then there’s third-party JavaScript.

In retrospect, it seems unbelievable that third-party JavaScript is even possible. I mean, putting arbitrary code—that can then inject even more arbitrary code—onto your website? That seems like a security nightmare!

I imagine if JavaScript were being specced today, it would almost certainly be restricted to the same origin by default. But I guess the precedent had been set with images and style sheets: they could be embedded regardless of whether their domain names matched yours. Still, this is executable code we’re talking about here: that’s quite a footgun that the web has given site owners. And boy, oh boy, has it been used by the worst people to do the most damage.

Again, as with cookies, if we were to imagine what the web would be like if JavaScript was restricted by a same-domain policy, there are certainly things that would be trickier to do.

  • Embedding video, audio, and maps would get a lot finickier.
  • Analytics would need to be self-hosted. I don’t think that would bother any site owners. An analytics platform like Google Analytics that tracks people across domains is doing it for its own benefit rather than that of site owners.
  • Advertising wouldn’t be creepy and annoying. Instead of what’s so euphemistically called “personalisation”, advertisers would have to rely on serving relevant ads based on the content of the site rather than an invasive psychological profile of the user. (I honestly think that advertisers would benefit from this kind of targetting.)

It’s harder to imagine putting the genie back in the bottle when it comes to third-party JavaScript than it is with third-party cookies. All the same, I wish that browsers made it easier to experiment with it. Just as I can choose to accept all cookies, reject all cookies, or only accept same-origin cookies, I wish I could accept all JavaScript, reject all JavaScript, or only accept same-origin JavaScript.

As it is, browsers are making it harder and harder to exercise any control over JavaScript at all. So we reach for third-party tools. We don’t call them JavaScript managers though. We call them ad blockers. But honestly, most of the ad-blocker users I know—myself included—are not bothered by the advertising; we’re bothered by the tracking. We should really call them surveillance blockers.

If third-party JavaScript weren’t the norm, not only would it make the web more secure, it would make it way more performant. Read the chapter on third parties in this year’s newly-released Web Almanac. The figures are staggering.

93% of pages include at least one third-party resource, 76% of pages issue a request to an analytics domain, the median page requests content from at least 9 unique third-party domains that represent 35% of their total network activity, and the most active 10% of pages issue a whopping 175 third-party requests or more.

I don’t think all the web’s performance ills are due to third-party scripts; developers are doing a bang-up job of making their sites big and bloated with their own self-hosted frameworks and code. But as long as third-party JavaScript is allowed onto a site, there’s a limit to how much good developers can do to improve the performance of their sites.

I go to performance-related conferences and you know who I’ve never seen at those events? The people who write the JavaScript for third-party tracking scripts. Those developers are wielding an outsized influence on the health of the web.

I’m very happy to see the work being done by Mozilla and Apple to normalise the idea of rejecting third-party cookies. I’d love to see the rejection of third-party JavaScript normalised in the same way. I know that it would make my life as a developer harder. But that’s of lesser importance. It would be better for the web.

CSS for all

There have been some great new CSS properties and values shipping in Firefox recently.

Miriam Suzanne explains the difference between the newer revert value and the older inherit, initial and unset values in a video on the Mozilla Developer channel:

display: revert;

In another video, Jen describes some new properties for styling underlines (on links, for example):

text-decoration-thickness:  0.1em;
text-decoration-color: red;
text-underline-offset: 0.2em;
text-decoration-skip-ink: auto;

Great stuff!

As far as I can tell, all of these properties are available to you regardless of whether you are serving your website over HTTP or over HTTPS. That may seem like an odd observation to make, but I invite you to cast your mind back to January 2018. That’s when the Mozilla Security Blog posted about moving to secure contexts everywhere:

Effective immediately, all new features that are web-exposed are to be restricted to secure contexts. Web-exposed means that the feature is observable from a web page or server, whether through JavaScript, CSS, HTTP, media formats, etc. A feature can be anything from an extension of an existing IDL-defined object, a new CSS property, a new HTTP response header, to bigger features such as WebVR.

(emphasis mine)

Buzz Lightyear says to Woody: Secure contexts …secure contexts everywhere!

Despite that “effective immediately” clause, I haven’t observed any of the new CSS properties added in the past two years to be restricted to HTTPS. I’m glad about that. I wrote about this announcement at the time:

I am in total agreement that we should be encouraging everyone to switch to HTTPS. But requiring HTTPS in order to use CSS? The ends don’t justify the means.

If there were valid security reasons for making HTTPS a requirement, I would be all for enforcing this. But these are two totally separate areas. Enforcing HTTPS by withholding CSS support is no different to enforcing AMP by withholding search placement.

There’s no official word from the Mozilla Security Blog about any change to their two-year old “effective immediately” policy, and the original blog post hasn’t been updated. Maybe we can all just pretend it never happened.

Periodic background sync

Yesterday I wrote about how much I’d like to see silent push for the web:

I’d really like silent push for the web—the ability to update a cache with fresh content as soon as it’s published; that would be nifty! At the same time, I understand the concerns. It feels more powerful than other permission-based APIs like notifications.

Today, John Holt Ripley responded on Twitter:

hi there, just read your blog post about Silent Push for acthe web, and wondering if Periodic Background Sync would cover a few of those use cases?

Periodic background sync looks very interesting indeed!

It’s not the same as silent push. As the name suggests, this is about your service worker waking up periodically and potentially fetching (and caching) fresh content from the network. So the service worker is polling rather than receiving a push. But I’ll take it! It’s definitely close enough for the kind of use-cases I’ve been thinking about.

Interestingly, periodic background sync also ties into the other part of what I was writing about: permissions. I mentioned that adding a site the home screen could be interpreted as a signal to potentially allow more permissions (or at least allow prompts for more permissions).

Well, Chromium has a document outlining metrics for attempting to gauge site engagement. There’s some good thinking in there.

Silent push for the web

After Indie Web Camp in Berlin last year, I wrote about Seb’s nifty demo of push without notifications:

While I’m very unwilling to grant permission to be interrupted by intrusive notifications, I’d be more than willing to grant permission to allow a website to silently cache timely content in the background. It would be a more calm technology.

Phil Nash left a comment on the Medium copy of my post explaining that Seb’s demo of using the Push API without showing a notification wouldn’t work for long:

The browsers allow a certain number of mistakes(?) before they start to show a generic notification to say that your site sent a push notification without showing a notification. I believe that after ~10 or so notifications, and that’s different between browsers, they run out of patience.

He also provided me with the name to describe what I’m after:

You’re looking for “silent push” as are many others.

Silent push is something that is possible in native apps. It isn’t (yet?) available on the web, presumably because of security concerns.

It’s an API that would ripe for abuse. I mean, just look at the mess we’ve made with APIs like notifications and geolocation. Sure, they require explicit user opt-in, but these opt-ins are seen so often that users are sick of seeing them. Silent push would be one more permission-based API to add to the stack of annoyances.

Still, I’d really like silent push for the web—the ability to update a cache with fresh content as soon as it’s published; that would be nifty! At the same time, I understand the concerns. It feels more powerful than other permission-based APIs like notifications.

Maybe there could be another layer of permissions. What if adding a site to your home screen was the first step? If a site is running on HTTPS, has a service worker, has a web app manifest, and has been added to the homescreen, maybe then and only then should it be allowed to prompt for permission to do silent push.

In other words, what if certain very powerful APIs were only available to progressive web apps that have successfully been added to the home screen?

Frankly, I’d be happy if the same permissions model applied to web notifications too, but I guess that ship has sailed.

Anyway, all this is pure conjecture on my part. As far as I know, silent push isn’t on the roadmap for any of the browser vendors right now. That’s fair enough. Although it does annoy me that native apps have this capability that web sites don’t.

It used to be that there was a long list of features that only native apps could do, but that list has grown shorter and shorter. The web’s hare is catching up to native’s tortoise.

Web talk

At the start of this month I was in Amsterdam for a series of back-to-back events: Indie Web Camp Amsterdam, View Source, and Fronteers. That last one was where Remy and I debuted talk we’d been working on.

The Fronteers folk have been quick off the mark so the video is already available. I’ve also published the text of the talk here:

How We Built The World Wide Web In Five Days

This was a fun talk to put together. The first challenge was figuring out the right format for a two-person talk. It quickly became clear that Remy’s focus would be on the events of the five days we spent at CERN, whereas my focus would be on the history of computing, hypertext, and networks leading up to the creation of the web.

Now, we could’ve just done everything chronologically, but that would mean I’d do the first half of the talk and Remy would do the second half. That didn’t appeal. And it sounded kind of boring. So then we come up with the idea of interweaving the two timelines.

That worked remarkably well. The talk starts with me describing the creation of CERN in the 1950s. Then Remy talks about the first day of the hack week. I then talk about events in the 1960s. Remy talks about the second day at CERN. This continues until we join up about half way through the talk: I’ve arrived at the moment that Tim Berners-Lee first published the proposal for the World Wide Web, and Remy has arrived at the point of having running code.

At this point, the presentation switches gears and turns into a demo. I do not have the fortitude to do a live demo, so this was all down to Remy. He did it flawlessly. I have so much respect for people brave enough to do live demos, and do them well.

But the talk doesn’t finish there. There’s a coda about our return to CERN a month after the initial hack week. This was an opportunity for both of us to close out the talk with our hopes and dreams for the World Wide Web.

I know I’m biased, but I thought the structure of the presentation worked really well: two interweaving timelines culminating in a demo and finishing with the big picture.

There was a forcing function on preparing this presentation: Remy was moving house, and I was already going to be away speaking at some other events. That limited the amount of time we could be in the same place to practice the talk. In the end, I think that might have helped us make the most of that time.

We were both feeling the pressure to tell this story well—it means so much to us. Personally, I found that presenting with Remy made me up my game. Like I said:

It’s been a real treat working with Remy on this. Don’t tell him I said this, but he’s kind of a web hero of mine, so this was a real honour and a privilege for me.

This talk could have easily turned into a boring slideshow of “what we did on our holidays”, but I think we managed to successfully avoid that trap. We’re both proud of this talk and we’d love to give it again some time. If you’d like it at your event, get in touch.

In the meantime, you can read the text, watch the video, or look at the slides (but the slides really don’t make much sense in isolation).

The Web Share API in Safari on iOS

I implemented the Web Share API over on The Session back when it was first available in Chrome in Android. It’s a nifty and quite straightforward API that allows websites to make use of the “sharing drawer” that mobile operating systems provide from within a web browser.

I already had sharing buttons that popped open links to Twitter, Facebook, and email. You can see these sharing buttons on individual pages for tunes, recordings, sessions, and so on.

I was already intercepting clicks on those buttons. I didn’t have to add too much to also check for support for the Web Share API and trigger that instead:

if (navigator.share) {
  navigator.share(
    {
      title: document.querySelector('title').textContent,
      text: document.querySelector('meta[name="description"]').getAttribute('content'),
      url: document.querySelector('link[rel="canonical"]').getAttribute('href')
    }
  );
}

That worked a treat. As you can see, there are three fields you can pass to the share() method: title, text, and url. You don’t have to provide all three.

Earlier this year, Safari on iOS shipped support for the Web Share API. I didn’t need to do anything. ‘Cause that’s how standards work. You can make use of APIs before every browser supports them, and then your website gets better and better as more and more browsers add support.

But I recently discovered something interesting about the iOS implementation.

When the share() method is triggered, iOS provides multiple ways of sharing: Messages, Airdrop, email, and so on. But the simplest option is the one labelled “copy”, which copies to the clipboard.

Here’s the thing: if you’ve provided a text parameter to the share() method then that’s what’s going to get copied to the clipboard—not the URL.

That’s a shame. Personally, I think the url field should take precedence. But I don’t think this is a bug, per se. There’s nothing in the spec to say how operating systems should handle the data sent via the Web Share API. Still, I think it’s a bit counterintuitive. If I’m looking at a web page, and I opt to share it, then surely the URL is the most important piece of data?

I’m not even sure where to direct this feedback. I guess it’s under the purview of the Safari team, but it also touches on OS-level interactions. Either way, I hope that somebody at Apple will consider changing the current behaviour for copying Web Share data to the clipboard.

In the meantime, I’ve decided to update my code to remove the text parameter:

if (navigator.share) {
  navigator.share(
    {
      title: document.querySelector('title').textContent,
      url: document.querySelector('link[rel="canonical"]').getAttribute('href')
    }
  );
}

If the behaviour of Safari on iOS changes, I’ll reinstate the missing field.

By the way, if you’re making progressive web apps that have display: standalone in the web app manifest, please consider using the Web Share API. When you remove the browser chrome, you’re removing the ability for users to easily share URLs. The Web Share API gives you a way to reinstate that functionality.

Geneva Copenhagen Amsterdam

Back in the late 2000s, I used to go to Copenhagen every for an event called Reboot. It was a fun, eclectic mix of talks and discussions, but alas, the last one was over a decade ago.

It was organised by Thomas Madsen-Mygdal. I hadn’t seen Thomas in years, but then, earlier this year, our paths crossed when I was back at CERN for the 30th anniversary of the web. He got a real kick out of the browser recreation project I was part of.

I few months ago, I got an email from Thomas about the new event he’s running in Copenhagen called Techfestival. He was wondering if there was some way of making the WorldWideWeb project part of the event. We ended up settling on having a stand—a modern computer running a modern web browser running a recreation of the first ever web browser from almost three decades ago.

So I showed up at Techfestival and found that the computer had been set up in a Shoreditchian shipping container. I wasn’t exactly sure what I was supposed to do, so I just hung around nearby until someone wandering by would pause and start tentatively approaching the stand.

If you’re at Techfestival.co in Copenhagen, drop in to this shipping container where I’ll be demoing WorldWideWeb.cern.ch

“Would you like to try the time machine?” I asked. Nobody refused the offer. I explained that they were looking at a recreation of the world’s first web browser, and then showed them how they could enter a URL to see how the oldest web browser would render a modern website.

Lots of people entered facebook.com or google.com, but some people had their own websites, either personal or for their business. They enjoyed seeing how well (or not) their pages held up. They’d take photos of the screen.

People asked lots of questions, which I really enjoyed answering. After a while, I was able to spot the themes that came up frequently. Some people were confusing the origin story of the internet with the origin story of the web, so I was more than happy to go into detail on either or both.

The experience helped me clarify in my own mind what was exciting and interesting about the birth of the web—how much has changed, and how much and stayed the same.

All of this very useful fodder for a conference talk I’m putting together. This will be a joint talk with Remy at the Fronteers conference in Amsterdam in a couple of weeks. We’re calling the talk How We Built the World Wide Web in Five Days:

The World Wide Web turned 30 years old this year. To mark the occasion, a motley group of web nerds gathered at CERN, the birthplace of the web, to build a time machine. The first ever web browser was, confusingly, called WorldWideWeb. What if we could recreate the experience of using it …but within a modern browser! Join (Je)Remy on a journey through time and space and code as they excavate the foundations of Tim Berners-Lee’s gloriously ambitious and hacky hypertext system that went on to conquer the world.

Neither of us is under any illusions about the nature of a joint talk. It’s not half as much work; it’s more like twice the work. We’ve both seen enough uneven joint presentations to know what we want to avoid.

We’ve been honing the material and doing some run-throughs at the Clearleft HQ at 68 Middle Street this week. The talk has a somewhat unusual structure with two converging timelines. I think it’s going to work really well, but I won’t know until we actually deliver the talk in Amsterdam. I’m excited—and a bit nervous—about it.

Whether it’s in a shipping container in Copenhagen or on a stage in Amsterdam, I’m starting to realise just how much I enjoy talking about web history.

Request mapping

The Request Map Generator is a terrific tool. It’s made by Simon Hearne and uses the WebPageTest API.

You pop in a URL, it fetches the page and maps out all the subsequent requests in a nifty interactive diagram of circles, showing how many requests third-party scripts are themselves generating. I’ve found it to be a very effective way of showing the impact of third-party scripts to people who aren’t interested in looking at waterfall diagrams.

I was wondering… Wouldn’t it be great if this were built into browsers?

We already have a “Network” tab in our developer tools. The purpose of this tab is to show requests coming in. The browser already has all the information it needs to make a diagram of requests in the same that the request map generator does.

In Firefox, there’s a little clock icon in the bottom left corner of the “Network” tab. Clicking that shows a pie-chart view of requests. That’s useful, but I’d love it if there were the option to also see the connected circles that the request map generator shows.

Just a thought.

Toast

Shockwaves rippled across the web standards community recently when it appeared that Google Chrome was unilaterally implementing a new element called toast. It turns out that’s not the case, but the confusion is understandable.

First off, this all kicked off with the announcement of “intent to implement”. That makes it sounds like Google are intending to, well, …implement this. In fact “intent to implement” really means “intend to mess around with this behind a flag”. The language is definitely confusing and this is something that will hopefully be addressed.

Secondly, Chrome isn’t going to ship a toast element. Instead, this is a proposal for a custom element currently called std-toast. I’m assuming that should the experiment prove successful, it’s not a foregone conclusion that the final element name will be called toast (minus the sexually-transmitted-disease prefix). If this turns out to be a useful feature, there will surely be a discussion between implementators about the naming of the finished element.

This is the ideal candidate for a web component. It makes total sense to create a custom element along the lines of std-toast. At first I was confused about why this was happening inside of a browser instead of first being created as a standalone web component, but it turns out that there’s been a fair bit of research looking at existing implementations in libraries and web components. So this actually looks like a good example of paving an existing cowpath.

But it didn’t come across that way. The timing of announcements felt like this was something that was happening without prior discussion. Terence Eden writes:

It feels like a Google-designed, Google-approved, Google-benefiting idea which has been dumped onto the Web without any consideration for others.

I know that isn’t the case. And I know how many dedicated people have worked hard on this proposal.

Adrian Roselli also remarks on the optics of this situation:

To be clear, while I think there is value in minting a native HTML element to fill a defined gap, I am wary of the approach Google has taken. A repo from a new-to-the-industry Googler getting a lot of promotion from Googlers, with Googlers on social media doing damage control for the blowback, WHATWG Googlers handling questions on the repo, and Google AMP strongly supporting it (to reduce its own footprint), all add up to raise alarm bells with those who advocated for a community-driven, needs-based, accessible web.

Dave Cramer made a similar point:

But my concern wasn’t so much about the nature of the new elements, but of how we learned about them and what that says about how web standardization works.

So there’s a general feeling (outside of Google) that there’s something screwy here about the order of events. A lot discussion and research seems to have happened in isolation before announcing the intent to implement:

It does not appear that any discussions happened with other browser vendors or standards bodies before the intent to implement.

Why is this a problem? Google is seeking feedback on a solution, not on how to solve the problem.

Going back to my early confusion about putting a web component directly into a browser, this question on Discourse echoes my initial reaction:

Why not release std-toast (and other elements in development) as libraries first?

It turns out that std-toast and other in-browser web components are part of an idea called layered APIs. In theory this is an initiative in the spirit of the extensible web manifesto.

The extensible web movement focused on exposing low-level APIs to developers: the fetch API, the cache API, custom elements, Houdini, and all of those other building blocks. Layered APIs, on the other hand, focuses on high-level features …like, say, an HTML element for displaying “toast” notifications.

Layered APIs is an interesting idea, but I’m worried that it could be used to circumvent discussion between implementers. It’s a route to unilaterally creating new browser features first and standardising after the fact. I know that’s how many features already end up in browsers, but I think that the sooner that authors, implementers, and standards bodies get a say, the better.

I certainly don’t think this is a good look for Google given the debacle of AMP’s “my way or the highway” rollout. I know that’s a completely different team, but the external perception of Google amongst developers has been damaged by the AMP project’s anti-competitive abuse of Google’s power in search.

Right now, a lot of people are jumpy about Microsoft’s move to Chromium for Edge. My friends at Microsoft have been reassuring me that while it’s always a shame to reduce browser engine diversity, this could actually be a good thing for the standards process: Microsoft could theoretically keep Google in check when it comes to what features are introduced to the Chromium engine.

But that only works if there is some kind of standards process. Layered APIs in general—and std-toast in particular—hint at a future where a single browser vendor can plough ahead on their own. I sincerely hope that’s a misreading of the situation and that this has all been an exercise in miscommunication and misunderstanding.

Like Dave Cramer says:

I hear a lot about how anyone can contribute to the web platform. We’ve all heard the preaching about incubation, the Extensible Web, working in public, paving the cowpaths, and so on. But to an outside observer this feels like Google making all the decisions, in private, and then asking for public comment after the feature has been designed.

Move Fast and Don’t Break Things by Scott Jehl

Scott Jehl is speaking at An Event Apart in Seattle—yay! His talk is called Move Fast and Don’t Break Things:

Performance is a high priority for any site of scale today, but it can be easier to make a site fast than to keep it that way. As a site’s features and design evolves, its performance is often threatened for a number of reasons, making it hard to ensure fast, resilient access to services. In this session, Scott will draw from real-world examples where business goals and other priorities have conflicted with page performance, and share some strategies and practices that have helped major sites overcome those challenges to defend their speed without compromises.

The title is a riff on the “move fast and break things” motto, which comes from a more naive time on the web. But Scott finds part of it relatable. Things break. We want to move fast without breaking things.

This is a performance talk, which is another kind of moving fast. Scott starts with a brief history of not breaking websites. He’s been chipping away at websites for 20 years now. Remember Positioning Is Everything? How about Quirksmode? That one's still around.

In the early days, building a website that was "not broken" was difficult, but it was difficult for different reasons. We were focused on consistency. We had deal with differences between browsers. There were two ways of dealing with browsers: browser detection and feature detection.

The feature-based approach was more sustainable but harder. It fits nicely with the practice of progressive enhancement. It's a good mindset for dealing with the explosion of devices that kicked off later. Touch screens made us rethink our mouse and hover-centric matters. That made us realise how much keyboard-driven access mattered all along.

Browsers exploded too. And our data networks changed. With this explosion of considerations, it was clear that our early ideas of “not broken” didn’t work. Our notion of what constituted “not broken” was itself broken. Consistency just doesn’t cut it.

But there was a comforting part to this too. It turned out that progressive enhancement was there to help …even though we didn’t know what new devices were going to appear. This is a recurring theme throughout Scott’s career. So given all these benefits of progressive enhancement, it shouldn’t be surprising that it turns out to be really good for performance too. If you practice progressive enhancement, you’re kind of a performance expert already.

People started talking about new performance metrics that we should care about. We’ve got new tools, like Page Speed Insights. It gives tangible advice on how to test things. Web Page Test is another great tool. Once you prove you’re a human, Web Page Test will give you loads of details on how a page loaded. And you get this great visual timeline.

This is where we can start to discuss the metrics we want to focus on. Traditionally, we focused on file size, which still matters. But for goal-setting, we want to focus on user-perceived metrics.

First Meaningful Content. It’s about how soon appears to be useful to a user. Progressive enhancement is a perfect match for this! When you first make request to a website, it’s usually for a web page. But to render that page, it might need to request more files like CSS or JavaScript. All of this adds up. From a user perspective, if the HTML is downloaded, but the browser can’t render it, that’s broken.

The average time for this on the web right now is around six seconds. That’s broken. The render blockers are the problem here.

Consider assets like scripts. Can you get the browser to load them without holding up the rendering of the page? If you can add async or defer to a script element in the head, you should do that. Sometimes that’s not an option though.

For CSS, it’s tricky. We’ve delivered the HTML that we need but we’ve got to wait for the CSS before rendering it. So what can you bundle into that initial payload?

You can user server push. This is a new technology that comes with HTTP2. H2, as it’s called, is very performance-focused. Just turning on H2 will probably make your site faster. Server push allows the server to send files to the browser before the browser has even asked for them. You can do this with directives in Apache, for example. You could push CSS whenever an HTML file is requested. But we need to be careful not to go too far. You don’t want to send too much.

Server push is great in moderation. But it is new, and it may not even be supported by your server.

Another option is to inline CSS (well, actually Scott, this is technically embedding CSS). It’s great for first render, but isn’t it wasteful for caching? Scott has a clever pattern that uses the Cache API to grab the contents of the inlined CSS and put a copy of its contents into the cache. Then it’s ready to be served up by a service worker.

By the way, this isn’t just for CSS. You could grab the contents of inlined SVGs and create cached versions for later use.

So inlining CSS is good, but again, in moderation. You don’t want to embed anything bigger than 15 or 20 kilobytes. You might want separate out the critical CSS and only embed that on first render. You don’t need to go through your CSS by hand to figure out what’s critical—there are tools that to do this that integrate with your build process. Embed that critical CSS into the head of your document, and also start preloading the full CSS. Here’s a clever technique that turns a preload link into a stylesheet link:

<link rel="preload" href="site.css" as="style" onload="this.rel='stylesheet'">

Also include this:

<noscript><link rel="stylesheet" href="site.css"></noscript>

You can also optimise for return visits. It’s all about the cache.

In the past, we might’ve used a cookie to distinguish a returning visitor from a first-time visitor. But cookies kind of suck. Here’s something that Scott has been thinking about: service workers can intercept outgoing requests. A service worker could send a header that matches the current build of CSS. On the server, we can check for this header. If it’s not the latest CSS, we can server push the latest version, or inline it.

The neat thing about service workers is that they have to install before they take over. Scott makes use of this install event to put your important assets into a cache. Only once that is done to we start adding that extra header to requests.

Watch out for an article on the Filament Group blog on this technique!

With performance, more weight doesn’t have to mean more wait. You can have a heavy page that still appears to load quickly by altering the prioritisation of what loads first.

Web pages are very heavy now. There’s a real cost to every byte. Tim’s WhatDoesMySiteCost.com shows that the CNN home page costs almost fifty cents to load for someone in America!

Time to interactive. This is is the time before a user can use what’s on the screen. The issue is almost always with JavaScript. The page looks usable, but you can’t use it yet.

Addy Osmani suggests we should get to interactive in under five seconds on a 3G network on a median mobile device. Your iPhone is not a median mobile device. A typical phone takes six seconds to process a megabyte of JavaScript after it has downloaded. So even if the network is fast, the time to interactive can still be very long.

This all comes down to our industry’s increasing reliance on JavaScript just to render content. There seems to be pendulum shifts between client-side and server-side rendering. It’s been great to see libraries like Vue and Ember embrace server-side rendering.

But even with server-side rendering, there’s still usually a rehydration step where all the JavaScript gets parsed and that really affects time to interaction.

Code splitting can help. Webpack can do this. That helps with first-party JavaScript, but what about third-party JavaScript?

Scott believes easier to make a fast website than to keep a fast website. And that’s down to all the third-party scripts that people throw in: analytics, ads, tracking. They can wreak havoc on all your hard work.

These scripts apparently contribute to the business model, so it can be hard for us to make the case for removing them. Tools like SpeedCurve can help people stay informed on the impact of these scripts. It allows you to set up performance budgets and it shows you when pages go over budget. When that happens, we have leverage to step in and push back.

Assuming you lose that battle, what else can we do?

These days, lots of A/B testing and personalisation happens on the client side. The tooling is easy to use. But they are costly!

A typical problematic pattern is this: the server sends one version of the page, and once the page is loaded, the whole page gets replaced with a different layout targeted at the user. This leads to a terrifying new metric that Scott calls Second Meaningful Content.

Assuming we can’t remove the madness, what can we do? We could at least not do this for first-time visits. We could load the scripts asyncronously. We can preload the scripts at the top of the page. But ideally we want to move these things to the server. Server-side A/B testing and personalisation have existed for a while now.

Scott has been experimenting with a middleware solution. There’s this idea of server workers that Cloudflare is offering. You can manipulate the page that gets sent from the server to the browser—all the things you would do for an A/B test. Scott is doing this by using comments in the HTML to demarcate which portions of the page should be filtered for testing. The server worker then deletes a block for some users, and deletes a different block for other users. Scott has written about this approach.

The point here isn’t about using Cloudflare. The broader point is that it’s much faster to do these things on the server. We need to defend our user’s time.

Another issue, other than third-party scripts, is the page weight on home pages and landing pages. Marketing teams love to fill these things with enticing rich imagery and carousels. They’re really difficult to keep performant because they change all the time. Sometimes we’re not even in control of the source code of these pages.

We can advocate for new best practices like responsive images. The srcset attribute on the img element; the picture element for when you need more control. These are great tools. What’s not so great is writing the markup. It’s confusing! Ideally we’d have a CMS drive this, but a lot of the time, landing pages fall outside of the purview of the CMS.

Scott has been using Vue.js to make a responsive image builder—a form that people can paste their URLs into, which spits out the markup to use. Anything we can do by creating tools like these really helps to defend the performance of a site.

Another thing we can do is lazy loading. Focus on the assets. The BBC homepage uses some lazy loading for images—they blink into view as your scroll down the page. They use LazySizes, which you can find on Github. You use data- attributes to list your image sources. Scott realises that LazySizes is not progressive enhancement. He wouldn’t recommend using it on all images, just some images further down the page.

But thankfully, we won’t need these workarounds soon. Soon we’ll have lazy loading in browsers. There’s a lazyload attribute that we’ll be able to set on img and iframe elements:

<img src=".." alt="..." lazyload="on">

It’s not implemented yet, but it’s coming in Chrome. It might be that this behaviour even becomes the default way of loading images in browsers.

If you dig under the hood of the implementation coming in Chrome, it actually loads all the images, but the ones being lazyloaded are only sent partially with a 206 response header. That gives enough information for the browser to lay out the page without loading the whole image initially.

To wrap up, Scott takes comfort from the fact that there are resilient patterns out there to help us. And remember, it is our job to defend the user’s experience.

Timelines of the web

Recreating the original WorldWideWeb browser was an exercise in digital archeology. With a working NeXT machine in the room, Kimberly was able to examine the source code for the first every browser and discover a treasure trove within. Like this gem in HTUtils.h:

#define TCP_PORT 80 /* Allocated to http by Jon Postel/ISI 24-Jan-92 */

Sure enough, by June of 1992 port 80 was documented as being officially assigned to the World Wide Web (Gopher got port 70). Jean-François Groff—who worked on the World Wide Web project with Tim Berners-Lee—told us that this was a moment they were very pleased about. It felt like this project of theirs was going places.

Jean-François also told us that the WorldWideWeb browser/editor was kind of like an advanced prototype. The idea was to get something up and running as quickly as possible. Well, the NeXT operating system had a very robust Text Object, so the path of least resistance for Tim Berners-Lee was to take the existing word-processing software and build a hypertext component on top of it. Likewise, instead of creating a brand new format, he used the existing SGML format and added one new piece: linking with A tags.

So the WorldWideWeb application was kind of like a word processor and document viewer mashed up with hypertext. Ted Nelson complains to this day that the original sin of the web was that it borrowed this page-based metaphor. But Nelson’s Project Xanadu, originally proposed in 1974 wouldn’t become a working reality until 2014—a gap of forty years. Whereas Tim Berners-Lee proposed his system in March 1989 and had working code within a year. There’s something to be said for being pragmatic and working with what you’ve got.

The web was also a mashup of ideas. Hypertext existed long before the web—Ted Nelson coined the term in 1963. There were conferences and academic discussions devoted to hypertext and hypermedia. But almost all the existing hypertext systems—including Tim Berners-Lee’s own ENQUIRE system from the early 80s—were confined to a local machine. Meanwhile networked computers were changing everything. First there was the ARPANET, then the internet. Tim Berners-Lee’s ambitious plan was to mash up hypertext with networks.

Going into our recreation of WorldWideWeb at CERN, I knew I wanted to convey this historical context somehow.

The World Wide Web officially celebrates its 30th birthday in March of this year. It’s kind of an arbitrary date: it’s the anniversary of the publication of Information Management: A Proposal. Perhaps a more accurate date would be the day the first website—and first web server—went online. But still. Let’s roll with this date of March 12, 1989. I thought it would be interesting not only to look at what’s happened between 1989 and 2019, but also to look at what happened between 1959 and 1989.

So now I’ve got two time cones that converge in the middle: 1959 – 1989 and 1989 – 2019. For the first time period, I made categories of influences: formats, hypertext, networks, and computing. For the second time period, I catalogued notable results: browsers, servers, and the evolution of HTML.

I did a little bit of sketching and quickly realised that these converging timelines could be represented somewhat like particle collisions. Once I had that idea in my head, I knew how I would be spending my time during the hack week.

Rather than jumping straight into the collider visualisation, I took some time to make a solid foundation to build on. I wanted to be sure that the timeline itself would be understable even if it were, say, viewed in the first ever web browser.

Progressive enhancement. Marking up (and styling) an interactive timeline that looks good in a modern browser and still works in the first ever web browser.

I marked up each timeline as an ordered list of h-events:

<li class="h-event y1968">
  <a href="https://en.wikipedia.org/wiki/NLS_%28computer_system%29" class="u-url">
    <time class="dt-start" datetime="1968-12-09">1968</time>
    <abbr class="p-name" title="oN-Line System">NLS</abbr>
  </a>
</li>

With the markup in place, I could concentrate on making it look halfway decent. For small screens, the layout is very basic—just a series of lists. When the screen gets wide enough, I lay those lists out horzontally one on top of the other. In this view, you can more easily see when events coincide. For example, ENQUIRE, Usenet, and Smalltalk all happen in 1980. But the real beauty comes when the screen is wide enough to display everthing at once. You can see how an explosion of activity in the early 90s. In 1994 alone, we get the release of Netscape Navigator, the creation of HTTPS, and the launch of Amazon.com.

The whole thing is powered by CSS transforms and positioning. Each year on a timeline has its own class that gets moved to the correct chronological point using calc(). I wanted to use translateX() but I couldn’t get the maths to work for that, so I had use plain ol’ left and right:

.y1968 {
  left: calc((1968 - 1959) * (100%/30) - 5em);
}

For events before 1989, it’s the distance of the event from 1959. For events after 1989, it’s the distance of the event from 2019:

.y2014 {
  right: calc((2019 - 2014) * (100%/30) - 5em);
}

(Each h-event has a width of 5em so that’s where the extra bit at the end comes from.)

I had to do some tweaking for legibility: bunches of events happening around the same time period needed to be separated out so that they didn’t overlap too much.

As a finishing touch, I added a few little transitions when the page loaded so that the timeline fans out from its centre point.

Et voilà!

Progressive enhancement. Marking up (and styling) an interactive timeline that looks good in a modern browser and still works in the first ever web browser.

I fiddled with the content a bit after peppering Robert Cailliau with questions over lunch. And I got some very valuable feedback from Jean-François. Some examples he provided:

1971: Unix man pages, one of the first instances of writing documents with a markup language that is interpreted live by a parser before being presented to the user.

1980: Usenet News, because it was THE everyday discussion medium by the time we created the web technology, and the Web first embraced news as a built-in information resource, then various platforms built on the web rendered it obsolete.

1982: Literary Machines, Ted Nelson’s book which was on our desk at all times

I really, really enjoyed building this “collider” timeline. It was a chance for me to smash together my excitement for web history with my enjoyment of using the raw materials of the web; HTML and CSS in this case.

The timeline pales in comparison to the achievement of the rest of the team in recreating the WorldWideWeb application but I was just glad to be able to contribute a little something to the project.

Hello WorldWideWeb.

WorldWideWeb

Nine people came together at CERN for five days and made something amazing. I still can’t quite believe it.

Coming into this, I thought it was hugely ambitious to try to not only recreate the experience of using the first ever web browser (called WorldWideWeb, later Nexus), but to also try to document the historical context of the time. Now that it’s all done, I’m somewhat astounded that we managed to achieve both.

Want to see the final result? Here you go:

worldwideweb.cern.ch

That’s the website we built. The call to action is hard to miss:

Launch WorldWideWeb

Behold! A simulation of using the first ever web browser, recreated inside your web browser.

Now you could try clicking around on the links on the opening doucment—remembering that you need to double-click on links to activate them—but you’ll quickly find that most of them don’t work. They’re long gone. So it’s probably going to be more fun to open a new page to use as your starting point. Here’s how you do that:

  1. Select Document from the menu options on the left.
  2. A new menu will pop open. Select Open from full document reference.
  3. Type a URL, like, say https://adactio.com
  4. Press that lovely chunky Open button.

You are now surfing the web through a decades-old interface. Double click on a link to open it. You’ll notice that it opens in a new window. You’ll also notice that there’s no way of seeing the current URL. Back then, the idea was that you would navigate primarily by clicking on links, creating your own “associative trails”, as first envisioned by Vannevar Bush.

But the WorldWideWeb application wasn’t just a browser. It was a Hypermedia Browser/Editor.

  1. From that Document menu you opened, select New file…
  2. Type the name of your file; something like test.html
  3. Start editing the heading and the text.
  4. In the main WorldWideWeb menu, select Links.
  5. Now focus the window with the document you opened earlier (adactio.com).
  6. With that window’s title bar in focus, choose Mark all from the Links menu.
  7. Go back to your test.html document, and highlight a piece of text.
  8. With that text highlighted, click on Link to marked from the Links menu.

If you want, you can even save the hypertext document you created. Under the Document menu there’s an option to Save a copy offline (this is the one place where the wording of the menu item isn’t exactly what was in the original WorldWideWeb application). Save the file so you can open it up in a text editor and see what the markup would’ve looked it.

I don’t know about you, but I find this utterly immersive and fascinating. Imagine what it must’ve been like to browse, create, and edit like this. Hypertext existed before the web, but it was confined to your local hard drive. Here, for the first time, you could create links across networks!

After five days time-travelling back thirty years, I have a new-found appreciation for what Tim Berners-Lee created. But equally, I’m in awe of what my friends created thirty years later.

Remy did all the JavaScript for the recreated browser …in just five days!

Kimberly was absolutely amazing, diving deep into the original source code of the application on the NeXT machine we borrowed. She uncovered some real gems.

Of course Mark wanted to make sure the font was as accurate as possible. He and Brian went down quite a rabbit hole, and with remote help from David Jonathan Ross, they ended up recreating entire families of fonts.

John exhaustively documented UI patterns that Angela turned into marvelous HTML and CSS.

Through it all, Craig and Martin put together the accomanying website. Personally, I think the website is freaking awesome—it’s packed with fascinating information! Check out the family tree of browsers that Craig made.

What a team!

Back at CERN

We got the band back together.

In September of 2013, I had the great pleasure and privilege of going to CERN with a bunch of very smart people. I’m not sure how I managed to slip by. We were there to recreate the experience of using the line-mode browser. As I wrote at the time:

Just to be clear, the line-mode browser wasn’t the world’s first web browser. That honour goes to Tim Berners-Lee’s WorldWideWeb programme. But whereas WorldWideWeb only ran on NeXT machines, the line-mode browser worked cross-platform and was, therefore, instrumental in demonstrating the power of the web as a universally-accessible medium.

In the run-up to the 30th anniversary of the original (vague but exciting) proposal for what would become the World Wide Web, we’ve been invited back to try to recreate the experience of using that first web browser, the one that one ever ran on NeXT machines.

I missed the first day due to travel madness—flying back from Interaction 19 in Seattle during snowmageddon to Heathrow and then to Geneva—but by the time I arrived, my hackmates had already made a great start in identifying the objectives:

  1. Give people an understanding of the user experience of the WorldWideWeb browser.
  2. Demonstrate that a read/write philosophy was there from the beginning.
  3. Give context—what was going on at the time?

That second point is crucial. WorldWideWeb wasn’t just a web browser; it was a browser/editor. That’s by far the biggest change in terms of the original vision of the web and what we ended up getting from Mosaic onwards.

Remy is working hard on the first point. He documented the first day and now on the second day, he’s made enormous progress already.

I’m focusing on point number three. I want to show the historical context for the World Wide Web. Here’s my plan…

Seeing as we’re coming up on the thirtieth anniversary, I thought it would be interesting to take the year of the proposal (1989) and look back in a time cone of thirty years previous to that at the influences on Tim Berners-Lee. I also want to look at what has happened with the web in the thirty years since the proposal. So the date of the proposal will be a centre point, with the timespan of 1959-1989 converging on it from the past, and the timespan of 1989-2019 diverging from it into the future. I hope it could make for a nice visualisation. Maybe I could try to get it look like data from a particle collision.

We’re here till the weekend and everyone else has already made tremendous progress. Kimberly has been hacking the Gibson …well, that’s what it looked like when she was deep in the code of the NeXT machine we’ve borrowed from Musée Bolo (merci beaucoup!).

We took a little time out for a tour of the data centre. Oh, and at lunch time, we sat with Robert Cailliau and grilled him with questions about the birth of the web. Quite a day!

Now it’s time for me to hit the hay and prepare for another day of hacking in this extraordinary place.