There’s no browser support yet but that doesn’t mean we can’t start adding prefers-reduced-data to our media queries today. I like the idea of switching between web fonts and system fonts.
Five pieces of low-hanging fruit:
- Unlabelled links and buttons
- No image descriptions
- Poor use of headings
- Inaccessible web forms
- Auto-playing audio and video
A follow-up to full-bleed layout post I linked to recently. Here’s how you can get the same effect with using CSS grid.
I like the use of the principle of least power not just in the choice of languages, but within the application of a language.
Match up images that have been posted in pairs to Twitter with the caption “same energy”. This is more fun and addictive than it has any right to be.
When you’ve got a single centered column but you want something (like an image) to break out and span the full width.
Did you know there’s an imagesrcset attribute you can put on link rel="preload" as="image" (along with an imagesizes attribute)?
I didn’t. (Until Amber pointed this out.)
I was helping a client with a bit of a performance audit this week. I really, really enjoy this work. It’s such a nice opportunity to get my hands in the soil of a website, so to speak, and suggest changes that will have a measurable effect on the user’s experience.
Not only is web performance a user experience issue, it may well be the user experience issue. Page speed has a proven demonstrable direct effect on user experience (and revenue and customer satisfaction and whatever other metrics you’re using).
It struck me that there’s a continuum of performance challenges. On one end of the continuum, you’ve got technical issues. These can be solved with technical solutions. On the other end of the continuum, you’ve got human issues. These can be solved with discussions, agreement, empathy, and conversations (often dreaded or awkward).
I think that, as developers, we tend to gravitate towards the technical issues. That’s our safe space. But I suspect that bigger gains can be reaped by tackling the uncomfortable human issues.
This week, for example, I uncovered three performance issues. One was definitely technical. One was definitely human. One was halfway between.
The technical issue was with web fonts. It’s a lot of fun to dive into this aspect of web performance because quite often there’s some low-hanging fruit: a relatively simple technical fix that will boost the performance (or perceived performance) of a website. That might be through resource hints (using link rel=“preload” in the HTML) or adjusting the font loading (using font-display in the CSS) or even nerdier stuff like subsetting.
In this case, the issue was with the file format of the font itself. By switching to woff2, there were significant file size savings. And the great thing is that @font-face rules allow you to specify multiple file formats so you can still support older browsers that can’t handle woff2. A win all ‘round!
The performance issue that was right in the middle of the technical/human continuum was with images. At first glance it looked like a similar issue to the fonts. Some images were being served in the wrong formats. When I say “wrong”, I guess I mean inappropriate. A photographic image, for example, is probably going to best served as a JPG rather than a PNG.
But unlike the fonts, the images weren’t in the direct control of the developers. These images were coming from a Content Management System. And while there’s a certain amount of processing you can do on the server, a human still makes the decision about what file format they’re uploading.
I’ve seen this happen at Clearleft. We launched an event site with lean performant code, but then someone uploaded an image that’s megabytes in size. The solution in that case wasn’t technical. We realised there was a knowledge gap around image file formats—which, let’s face it, is kind of a techy topic that most normal people shouldn’t be expected to know.
But it was extremely gratifying to see that people were genuinely interested in knowing a bit more about choosing the right format for the right image. I was able to provide a few rules of thumb and point to free software for converting images. It empowered those people to feel more confident using the Content Management System.
It was a similar situation with the client site I was looking at this week. Nobody is uploading oversized images in order to deliberately make the site slower. They probably don’t realise the difference that image formats can make. By having a discussion and giving them some pointers, they’ll have more knowledge and the site will be faster. Another win all ‘round!
At the other end of continuum was an issue that wasn’t technical. From a technical point of view, there was just one teeny weeny little script. But that little script is Google Tag Manager which then calls many, many other scripts that are not so teeny weeny. Third party scripts …the bane of web performance!
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!
Remember when I did a countdown of the top four web performance challenges? At the number one spot is other people’s JavaScript.
Now one technical solution would be to remove the Google Tag Manager script. But that’s probably not very practical—you’ll probably just piss off some other department. That said, if you can’t find out which department was responsible for adding the Google Tag Manager script in the first place, it might we well be an option to remove it and then wait and see who complains. If no one notices it’s gone, job done!
More realistically, there’s someone who’s added that Google Tag Manager script for their own valid reasons. You’ll need to talk to them and understand their needs.
Again, as with images uploaded in a Content Management System, they may not be aware of the performance problems caused by third-party scripts. You could try throwing numbers at them, but I think you get better results by telling the story of performance.
Use tools like Request Map Generator to help them visualise the impact that third-party scripts are having. Talk to them. More importantly, listen to them. Find out why those scripts are being requested. What are the outcomes they’re working towards? Can you offer an alternative way of providing the data they need?
I think many of us developers are intimidated or apprehensive about approaching people to have those conversations. But it’s necessary. And in its own way, it can be as rewarding as tinkering with code. If the end result is a faster website, then the work is definitely worth doing—whether it’s technical work or people work.
Personally, I just really enjoy working on anything that will end up improving a website’s performance, and by extension, the user experience. If you fancy working with me on your site, you should get in touch with Clearleft.
There’s a new image format on the browser block and it’s very performant indeed. Jake has all the details you didn’t ask for.
The World Ocean is as close as you can get to outer space without leaving Earth. It’s an entirely different universe, nothing like the life we have on land.
These wonderfully realistic photo effects from Lynn are quite lovely!
I added a dark mode to my website a while back. It was a fun thing to do during Indie Web Camp Amsterdam last year.
I tied the colour scheme to the operating system level. If you choose a dark mode in your OS, my website will adjust automatically thanks to the prefers-color-scheme: dark media query.
But I’ve seen notes from a few friends, not about my site specifically, but about how they like having an explicit toggle for dark mode (as well as the media query). Whenever I read those remarks, I’d think “I’m really not sure I’ve got time to deal with adding that kind of toggle to my site.”
But then I realised, “Jeremy, you absolute muffin! You’ve had a theme switcher on your website for almost two decades now!”
Doh! I had forgotten about that theme switcher. It dates back to the early days of CSS. I wanted my site to be a demonstration of how you could apply different styles to the same underlying markup (this was before the CSS Zen Garden came along). Those themes are very dated now, but if you like you can view my site with a Zeldman theme or a sci-fi theme.
To offer a dark-mode theme for my site, all I had to do was take the default stylesheet, pull out the custom properties from the prefers-color-scheme: dark media query, and done. It took less than five minutes.
So if you want to view my site in dark mode, it’s one of the options in the “Customise” dropdown on every page of the website.
This is a very nifty use of CSS gradients!
Chris has put together one of his indispensable deep dives, this time into responsive images. I can see myself referring back to this when I need to be reminded of the syntax of srcset and sizes.
Progressive Enhancement allows us to use the latest and greatest features HTML, CSS and JavaScript offer us, by providing a basic, but robust foundation for all.
Some great practical examples of progressive enhancement on one website:
type="module" to enhance a form with JavaScript,picture element to provide webp images in HTML.All of those enhancements work great in modern browsers, but the underlying functionality is still available to a browser like Opera Mini on a feature phone.
I had the great pleasure of visiting the Museum Plantin-Moretus in Antwerp last October. Their vast collection of woodblocks are available to dowload in high resolution (and they’re in the public domain).
14,000 examples of true craftmanship, drawings masterly cut in wood. We are supplying this impressive collection of woodcuts in high resolution. Feel free to browse as long as you like, get inspired and use your creativity.
A great little mini case-study from Eric—if you’re exporting transparent PNGs from a graphic design tool, double-check the colour-depth settings!
I’d been saving the PNGs with no bit depth restrictions, meaning the color table was holding space for 224 colors. That’s… a lot of colors, roughly 224 of which I wasn’t actually using.
A nice succint explanation of using the srcset and sizes attributes on the img element—remember, you probably don’t need picture and source elements if your use case is swapping out different sized versions of the same image.
One caveat thought: you do need to know the dimensions of the images. If you’re dealing with unknown or user-generated photos, that can be an issue.
This is the transcript of a brilliant presentation by Scott—read the whole thing! It starts with a much-needed history lesson that gets to where we are now with the dismal state of performance on the web, and then gives a whole truckload of handy tips and tricks for improving performance when it comes to styles, scripts, images, fonts, and just about everything on the front end.
Essential!
Aaron outlines some sensible strategies for serving up images, including using the Cache API from your service worker script.
The Web is smothering in useless images. These clichéd, stock images communicate absolutely nothing of value, interest or use. They are one of the worst forms of digital pollution because they take up space on the page, forcing more useful content out of sight. They also slow down the site’s ability to download quickly.