Tags: development

Let’s Use the Nonexistent ::nth-letter Selector Now | CSS-Tricks

Eight years ago, I asked some questions. Here are some answers.

Two Paradigms for Enhancing HTML Tags | That HTML Blog

This really gets to the heart of one of the biggest benefits of HTML web components: composability. You can nest your regular markup inside multiple custom elements; something that is can’t do.

The other exciting approach doesn’t exist yet: custom attributes. Again, they’d be a great way of using composability to turbo-charge your existing HTML in all sorts of ways.

The end of responsive images - Piccalilli

Hallelujah! Support for sizes="auto" is finally landing in Firefox and Safari! Praise be!

HTML Video Poster Image: Enable Responsive Images and ALT Text for Poster by allowing a child IMG Element (with an optional Picture Element wrapper) to Control the Video Poster Image · Issue #10378 · whatwg/html

This is such a brilliant idea! Why not allow an img element inside video element in order to provide a responsive, accessible poster image?

Alistair Davidson / validation-enhancer · GitLab

Here’s another nice progressive web component for your forms, this time for showing error messages.

Never Lose Form Progress Again :: Aaron Gustafson

Here’s an excellent progressive web component from Aaron—wrap a custom element around your exising form and your good to go:

At its core, form-saver is a small web component that wraps a form, keeps an eye on it, stores values in localStorage, and restores them when the page loads again. Better yet, it clears out saved data after a successful submission so you’re not accidentally resurrecting stale information the next time someone stops by.

Design and Engineering, As One · Matthias Ott

A thoughtful piece by Matthias that’s a must-read for both designers and developers.

No-stack web development – David Bushell – Web Dev (UK)

A stack is also technical debt, non-transferable knowledge, accelerated obsolescence, and vendor lock-in. That means fragility and overall unnecessary complication. Popular stacks inevitably turn into cargo cults that build in spite of the web, not for it.

The web platform does not require build toolchains. Always default to, and regress to, the fundamentals of CSS, HTML, and JavaScript. Those core standards are the web stack.

Web Day Out - 12 March 2026 — Polytechnic

This was another fantastic conference from the Clearleft team, and one that I hope is repeated next year. It is absolutely incredible what you can do in the browser these days, and even though I thought I was keeping up with the latest developments, it astounded me how far things have come.

Four years ago I wrote about something that has long puzzled me in the world of front-end development. Trust:

The mindset I’ve noticed is that many developers are suspicious of browser features but trusting of third-party libraries.

Developers are more likely to trust, say, Bootstrap than they are to trust CSS grid or custom properties. Developers are more likely to trust React than they are to trust web components.

That post got some thoughtful responses but I never really understood the imbalance of trust and suspicion:

I’m kind of confused by this prevalent mindset of trusting third-party code more than built-in browser features.

But something happened recently that helped me understand that mindset better.

I wrote a while back about how the datalist element on iOS has been completely fucked up. It’s worse than if Safari simply didn’t support it.

Breaking the web like that should be a five-alarm fire, but nobody is in any rush to fix it. I recall a similar lackadaisical attitude when Safari completely broke their implentation of IndexedDB.

I had it in my head that browser features followed a forward path generally. They’d be iterated on and improved on to iron out any glitches, but it was reasonable to expect things to get better with each new version of a browser.

Now I see that’s not necessarily the case.

Had I used an over-engineered JavaScript library instead of the datalist element, I wouldn’t be facing the current situation of having to use browser-sniffing to avoid sending a standard HTML element to any browser on iOS.

Sure, that third-party JavaScript would mean that users are downloading more code, and it probably wouldn’t work well with assistive technology, but as long as I didn’t touch it, it would continue to work. That should be true of web standards—I should be able to use them secure in the knowledge that they won’t suddenly shit the bed.

Perhaps I should be grateful to Apple for dispelling my naïveté. I now have much more empathy and understanding for web developers who are suspicious of web standards and prefer to use third-party libraries instead.

Good job, Apple. Happy anniversary.

CSS or BS?

We show you a CSS property name. You tell us if it’s real or if we made it up. That’s it. It starts easy. It does not stay easy.

The Great CSS Expansion | Butler’s Log

Web development follows a familiar cycle. First we glue together a solution with whatever we have — JavaScript, image hacks, Flash, anything. Then the platform matures, and CSS or HTML eventually makes that same workaround native. Rounded corners, custom fonts, smooth scrolling, sticky positioning: all of these started as JavaScript-heavy hacks before CSS turned them into a single declaration.

We are in another one of those transition moments. A new wave of long-requested CSS features is finally landing, and many of them are explicitly designed to replace patterns that used to require JavaScript. Not as approximations — as first-class platform primitives that handle the edge cases, run in the right thread, and need zero dependencies.

Progressive Web Components | Ariel Salminen

I’m slapping my forehead—progressive web components is a perfect name for what I’ve been calling HTML web components. Why didn’t I think of that?

A Progressive Web Component is a native Custom Element designed in two layers: a base layer of HTML and CSS that renders immediately, without JavaScript, and an enhancement layer of JavaScript that adds reactivity, event handling, and more advanced templating.

How to be a web developer: Stuff Everybody Knows

This is a guide to how to be a web developer.

Really good advice from Laurie.

What this site is not is a tutorial. Tutorials are very specific to a time and a technology. This is intended to be a guide to tell you all the things you can learn, so you can then go off and learn them.

Web of State of the Browser Day Out

A lovely post from Remy about State Of The Browser and Web Day Out.

On March 12th, 1989, Tim Berners-Lee submitted Information Management: A Proposal. This would form the basis of what became the World Wide Web.

On March 12th, 2026, Web Day Out happened in Brighton.

Coincidence?

Yes. Yes, it is a coincidence. But it’s a pretty nice coincidence, you must admit.

It was a day dedicated to the World Wide Web. Not just the foundational languages of the web—HTML, CSS, and JavaScript—but also the foundational ideas of the web.

“Share what you know!” That was the original motto of the World Wide Web project. That was the motto of Web Day Out too.

Look, I’m biased because I put the line-up together but honestly, all of the speakers were superb! So much knowledge delivered in such entertaining fashion.

I had a blast. And I’ll give myself a little pat on the back for how I grouped the talks into rhyming couplets:

Browsers: Jemima talked about what you can do with just HTML and CSS these days, and Rachel followed up with how to come up with your own browser support strategy.

Performance: Aleth made the case for multi-page progressive web apps that work under any network conditions, and Harry followed up with an impassioned rant about how much time and energy has been wasted on over-engineered single-page apps that ignore what browsers can do.

Styling: Manuel walked us through a whole new approach to writing modern CSS, and Rich followed up with a whirlwind tour of all the great typographic possibilities in CSS.

Standards Jake took us on the standards journey to customisable select elements, including anchor positioning and popovers, and then Lola showed us exactly what it takes to add a new feature to a web browser.

Everything flowed together really nicely.

I was a little apprehensive going into Web Day Out that it would just be preaching to the converted. And sure, there were plenty of veteran devs there who already knew the value of progressive enhancement and making the most of web standards. But I was gratified to also see lots of younger faces in the crowd.

I was talking to one young developer afterwards and she told me what an eye-opening experience it was. Whereas before she would have defaulted to a framework-driven single-page app for everything, now she’s got the knowledge to make an appropriate architectural choice.

Mission accomplished!

If you couldn’t make it to Web Day Out and you want to experience some RAMO, here’s the chatter on Bluesky and Mastodon, lovely photos by Marc, a post by Dave, and a lovely post by Amber.

Thank you so much to everyone who came. I think you’ll agree it was a most excellent day out.

The Session has been online in some form since the late 1990s. That’s long before web fonts existed.

To begin with, Times New Roman was the only game in town if you wanted serif type on a website. When Microsoft introduced Georgia it was a godsend. A beautiful typeface designed by Matthew Carter for the screen. I put it right at the start of my font stack for The Session.

Later, web fonts came along. Boy, does that short sentence belie the drama! There were very heated discussions about whether web browsers should provide this ability at all, and what it would mean for type foundries.

Microsoft led the way with their prorietary EOT format. Then everyone agreed on WOFF. Finally we got WOFF2, Electric Boogaloo.

Perhaps more important than that, we got intermediaries. Typekit, Fontdeck, and then the big daddy, Google Fonts.

That’s pretty much the state of play today. Oh yeah, and we’ve got variable fonts now.

I remember Nick Sherman presenting the idea of variable fonts at an Ampersand event years ago. I remember thinking “great idea, but it’ll never happen.” Pure science fiction. I thought the same thing when I first saw a conference presentation about a miraculous image format called Scalable Vector Graphics.

Sometimes I like to stop and take stock of what we take for granted in web browsers now. Web fonts. Variable web fonts. SVG. Flexbox. Grid. Media queries. Container queries. Fluid typography. And I haven’t even mentioned how we were once limited to just 216 colours on the web.

Georgia

Given all the advances in web typography, you might be wondering how my font strategy for The Session changed over the years.

It didn’t.

I mean, sure, I added fluid typography. That was a natural extension of my love for liquid layouts and, later, responsive design. But the font stack itself? That was still Georgia all the way.

Y’see, performance has always been a top priority for The Session. If I was going to replace a system font with a web font that the user had to download, it really needed to be worth it.

Over the years I dabbled with different typefaces but none of them felt quite right to me. And I still think Georgia is a beautiful typeface.

“But your website will look like lots of other websites!” some may cry. That used to be true when all we had was system fonts. But now that web fonts have become the norm, it’s actually pretty unusual to see Georgia in the wild.

Lora

Recently I found a font I liked. Part of why I like it is that it shares a lot of qualities with Georgia. It’s Lora by Olga Karpushina and Alexei Vanyashin.

I started to dabble with it and began seriously contemplating using it on The Session.

It’s a variable font, which is great. But actually, I’m not using that many weights on The Session. I could potentially just use a non-variable variety. It comes in fixed weights of regular, medium, semibold, and bold.

Alas, the regular weight (400) is a bit too light and the medium weight (500) is a bit too heavy. My goldilocks font weight is more like 450.

Okay, so the variable font it is. That also allows me to play around with some subtle variations in weights. As the font size gets bigger for headings, the font weight can reduce ever so slightly. And I can adjust the overall font weight down in dark mode (there’s no grading feature in this font, alas).

Subsetting

Lora supports a lot of alphabets, which is great—quite a few alphabets turn up on The Session occasionally. But this means that the font file size is quite large. 84K.

Subsetting to the rescue!

I created a subset of Lora that has everything except Cyrillic, Greek, and Latin Extended-B. I created another subset that only has Cyrillic, Greek, and Latin Extended-B. Now I’ve got two separate font files that are 48K and 41K in size.

I wrote two @font-face declarations for the two files. They’ve got the same font-family (Lora), the same font-weight (400 700), and the same font-style (normal) but they’ve got different values for unicode-range. That way, browsers know to only use appropriate file when characters on the page actually match the unicode range.

The first file is definitely going to be used. The second one might not even be needed on most pages.

I want to prioritise the loading of that first subsetted font file so it gets referenced in a link element with rel="preload".

The switcheroo

As well as file size, my other concern was how the swapping from Georgia to Lora would be perceived, especially on a slow connection. I wanted to avoid any visible rejiggering of the content.

This is where size-adjust comes in, along with its compadres ascent-override and descent-override.

Rather than adjusting the default size of Lora to match that of Georgia, I want to do it the other way around; adjust the fallback font to match the web font.

Here’s how I’m doing it:

@font-face {
    font-family: 'Fallback for Lora';
    src: local('Georgia');
    size-adjust: 105.77%;
    ascent-override: 95.11%;
    descent-override: 25.9%;
}

And then my font stack is:

font-family: Lora, 'Fallback for Lora', Georgia, serif;

It’s highly unlikely that any device out there has a system font called “Fallback for Lora” so I can be pretty confident that the @font-face adjustment rules will only get applied to browsers that have the right local font, Georgia.

But where did those magic numbers come from for size-adjust, ascent-override, and descent-override?

They came from Katie Hempenius. As well as maintaing a repo of font metrics, she provides the formula needed to calculate all three values. Or you could use this handy tool to eyeball it.

With that, Georgia gets swapped out for Lora with a minimum of layout shift.

First-timers and repeat visitors

Even with the layout shift taken care of, do I want to serve up web fonts to someone on a slow connection?

It depends. Specifically, it depends on whether it’s their first time visiting.

The Session already treats first time visitors differently to repeat visitors. The first time you visit the site, critical CSS is embedded in the head of the HTML page instead of being referenced in an external style sheet. Only once the page has loaded does the full style sheet also get downloaded and cached.

I decided that my @font-face rules pointing to the web fonts are not critical CSS. If it’s your first time visiting, those CSS rules only get downloaded after the page is done loading.

And unless you’re on a fast connection, you won’t see Georgia get swapped out for Lora. That’s because I’ve gone with a font-display value of “optional”.

Most people use “swap”. Some people use “fallback”. You’ve got to be pretty hardcore to use “optional”.

But the next page you go to, or the next time you come to the site, you more than likely will see Lora straight away. That’s because of the service worker I’ve got quietly putting static assets into the Cache API: CSS, JavaScript, and now web fonts.

So even though I’m prioritising snappy performance over visual consistency, it’s a trade-off that only really comes into play for first visits.

Next

I’m pretty happy with the overall strategy. Still, I’m not going to just set it and forget it. I’ll be monitoring the CRUX data for The Session keeping a particular eye on cumulative layout shift.

Before adding web fonts, the cumulative layout shift on The Session was zero. I think I’ve taken all the necessary steps to keep it nice and low, but if I’m wrong I’ll need to revisit my strategy.

Update: Big thanks to Roel Nieskens—of Wakamai Fondue fame—who managed to get the file size of my main subsetted font down even further; bedankt!

In my previous post, I mentioned that I’ve used the web install API in production. Specifically, I’ve used it on The Session. In order to do that, I had to register for the origin trial.

I’ve just signed up for another origin trial. This time it’s for the proposed focusgroup attribute:

The focusgroup HTML attribute is a proposed declarative way to add keyboard arrow-key navigation to composite widgets such as toolbars, tablists, menus, listboxes, etc. without writing any roving-tabindex JavaScript. One attribute replaces hundreds of lines of boilerplate.

I’ve got an HTML web component on The Session called tab-controls. And yes, there’s a bunch of code in there to listen for keyboard events and respond appropriately. I would very much like to rip that code out.

So now that I’ve opted into the origin trial, I’ve added this to my HTML:

<tab-controls role="tablist" focusgroup="tablist">

If this focusgroup attribute takes off, I’ll be able to remove the role attribute but for now, it’s very much needed.

In the JavaScript for my tab-controls custom element, I need to be able to detect support for focusgroup. Here’s how I’m doing it:

if (!this.focusgroup) {
// do all my key handling stuff here
}

Here’s the important thing: don’t use getAttribute('focusgroup') to test for browser support. That will return true if the attribute is in the HTML. But the attribute will only get converted into a property if the browser understands it.

Jake has a lot more detail on the differences between attributes and properties.

Anyway, I figured I’d share that little snippet in case you too were interested in trying out the focusgroup proposal using progressive enhancement.

I have websites in my dock on my computer. I have websites on the home screen of my phone. When I open these websites from the dock or from the home screen, they behave just like native apps. It’s brilliant!

But knowing that you can add a website to the dock or to the home screen remains arcane knowledge. If you don’t know it’s possible, most web browsers aren’t going to tell you it’s an option. As a site owner, you pretty much have to explain to your users what they can do.

Lately it feels like there’s been some movement to change this situation. Or, at the very least, there’s been some discussion.

As a site owner, what you want is a way for someone visiting your site to press a button to initiate the process of adding the site to the dock or the home screen.

From what I can see from the discussion, there are two contenders for how to do this: BeforeInstallPromptEvent versus navigator.install.

I’ve used both APIs in production, so I’d like to offer my balanced feedback on both:

• BeforeInstallPromptEvent sucks.
• navigator.install rocks.

To add more detail…

The BeforeInstallPromptEvent API relies on you capturing and delaying an event that may or not fire at all.

Based on some arbitrary heuristics, Chrome—for example—will prompt the user to install the current website. This easily-dismissable prompt looks indistinguishable from a prompt to sign up to a newsletter or grant permission for cookies, so most people dismiss it. The idea with BeforeInstallPromptEvent is that you capture that prompt, prevent it from prompting, and then release it when you think it’s an appropriate time.

If you think it takes mental gymnastics to understand that, just imagine what it’s like trying to implement it!

The whole thing rests on this flawed idea of an install prompt being shown when certain conditions are met. Other browser vendors rightly point out that users should be able to install any website they want. Ideally it should have a manifest file. But making a service worker a requirement is a step too far (and I say that as someone who literally wrote a book about service workers).

Contrast that with the Web Install API, AKA navigator.install.

Based on a user interaction—like a click on a button—the browser initiates the installation process. The user still has to confirm they want to do this, of course. You know how geolocation or web notifactions work? It’s like that. You can’t trigger any of those APIs without the user’s permission.

That’s it. No contest.

It would be absolutely wonderful if more browsers supported navigator.install. It would be a pain in the ass if they decided to support BeforeInstallPromptEvent instead.

The Artisanal Web | Another Rodeo

I feel very seen here. This describes how I built The Session:

There are still people building the web by hand, very much like we did it in the early days. They know all about what’s possible using modern tooling, yet they choose to expend their time and attention to the craft of doing it by hand. They care about the craft, and they care about what they’re making. They believe in their unique skill and vision over engagement strategies and analytics and content algorithms. They don’t need a platform, or they’ll build their own.