This twitter account is not operated by Lea Verou. It retweets all of Lea's dev stuff! Follow her directly (@LeaVerou) to read her views on non dev stuff too.
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Joined July 2013
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Lea Verou Dev Tweets retweeted
🔥 New blog post: The best way to use icons in Web UIs
What if I told you, you could use CSS to *insert* and *tweak* icons without touching any HTML?
And that you can manage them alongside your other design tokens?
lea.verou.me/blog/2026/icons…
Lea Verou Dev Tweets retweeted
This is hot. (and nice live specimen harness!)
We've been building a broader take on this for ~10mo w/ github.com/GoogleChrome/mode… covering nearly all of these CSS primitives plus 200 more guides across DOM, forms, perf, a11y.
To keep it token-efficient we cull all the stuff that models know by default, and then vector search (all local) to pull just the relevant guide. Evals too, ofc. yadda yadda.
Anyway. I think you may like it. (And I like what you got here too :)
Lea Verou Dev Tweets retweeted
🎨 Ever wondered why oklch() is so odd?
Why adjusting L doesn't produce good color ramps?
And why TF is L=100% not white?!?
I just wrote a thorough explanation of why this happens¹: github.com/web-platform-test…
👍 Upvote the GitHub issue if you want this fixed in browsers!
¹ Spoiler alert: it’s the lack of gamut mapping
ALT Illustration of the problem (screenshot from issue)
Lea Verou Dev Tweets retweeted
this css-only annotation library is so cool and elegant!
built by Maxim Syabro. check out the demo site here: neat-annotations.syabro.com/
Lea Verou Dev Tweets retweeted
Smart. iPhone Duo shifts to a dual layout when slightly creased like a book.
Lea Verou Dev Tweets retweeted
Fuck you. Whoever made this site. You win.
I’ve never had a site get my blood boiling like this before
This is so messed up.
opusfived.dev
Lea Verou Dev Tweets retweeted
Big hello to Lea Verou who will be on stage at dotJS! 🙌
@LeaVerou will be speaking about: No-build: pipe dream, or near future?
Almost every JS dev uses bundlers. Few actually like it. The mavericks who try to go no-build learn the hard way why it's still fringe. Are we stuck with bundlers forever, or is there light at the end of the tunnel (and is that light an oncoming train)? Lea takes a pragmatic look at what drives bundler usage, how well the web platform addresses those needs today and in the near future, what's still missing for no-build architectures to become viable, and whether AI changes the equation.
Lea has been improving the Web for nearly two decades. In her 14 years in the CSS WG, she designed many features you use daily. As a twice-elected W3C TAG member, she helped document the Web's Design Principles. She's also a TC39 delegate and WHATWG contributor, and in 2025 was awarded Pathfinder for Standards by the OpenJS Foundation for her overall work and impact. She holds a PhD from MIT, where she spent a decade researching and teaching at the intersection of usability, design, and web technologies.
Catch Lea live at dotJS.
🟡 dotjs.io
Lea Verou Dev Tweets retweeted
THIS. In fact, the average code quality I get from @claudeai is better than at least 99.9% of pre-AI human devs in my experience.
"You don’t need a scientific study to realize the mean quality of human-authored software leaned towards slop even before AI was around. How many times have you been frustrated by an app or website that just didn’t work right?"
abeautifulsite.net/posts/mos…
Lea Verou Dev Tweets retweeted
🔥 New blog post: “The best dark mode toggle is probably none”
My post on two-state dark mode toggles made the rounds. But should you have a (persistent) dark mode toggle at all?
I have since been convinced that for most websites, the answer is no.
lea.verou.me/blog/2026/dark-…
Lea Verou Dev Tweets retweeted
🔥 New blog post: Dark mode toggles that expose three visible states (system, light, dark) seem like the best option.
Until you think about user goals, that is.
Before rushing to disagree, hear me out.
lea.verou.me/blog/2026/dark-…
PS: As a data point, @jaffathecake was converted after reading this 😅
Lea Verou Dev Tweets retweeted
I had to edit the description and restart the poll because apparently EVERYONE misunderstood what this is asking.
These are the only transitions that are in scope for YES:
✅ System (dark) → dark
✅ System (light) → light
NOT:
❌ System (dark) → light
❌ System (light) → dark
❌ light → *
❌ dark → *
Also NOT:
❌ "[Other people] do this" I'm asking about YOU
❌ "I like three states for testing" I'm asking about YOU as a user. Debugging was explicitly out of scope.
❌ "By mistake" This is about intentional use
📊 For websites that use a tri-state dark mode toggle (system, light, dark), have you EVER clicked on the override that matches your current system theme?
E.g. going from System to Light on a light OS (which produces no visible change).
Experimentation aside obvs.
Poll at github.com/LeaVerou/blog/dis…
If the answer is yes, do tell me more! What was your thinking at the time? What were you trying to achieve? What made you seek the toggle in the first place if the website already looked fine?
Lea Verou Dev Tweets retweeted
📊 For websites that use a tri-state dark mode toggle (system, light, dark), have you EVER clicked on the override that matches your current system theme?
E.g. going from System to Light on a light OS (which produces no visible change).
Experimentation aside obvs.
Poll at github.com/LeaVerou/blog/dis…
If the answer is yes, do tell me more! What was your thinking at the time? What were you trying to achieve? What made you seek the toggle in the first place if the website already looked fine?
Lea Verou Dev Tweets retweeted
Yup, this tracks.
Just like those in the 90s who were against the Web and if you asked them about their experiences with the Web they were always minimal to none.
Lea Verou Dev Tweets retweeted
If declarations in conditionals were possible ( @TC39 proposal being discussed right now!) what would you expect this to log?
let foo = 1;
if (let foo = 0) { console.log(foo) }
else { console.log(foo) }
Don't think too hard.
37%1
41%0
1%undefined
22%Nothing, it throws
145 votes • Final results Lea Verou Dev Tweets retweeted
I’ve often said that user interfaces that are designed to work well for users with ADHD actually work better for everyone.
This quoted post is unavailable.
Lea Verou Dev Tweets retweeted
“We don’t stop flying planes because crashes happen. We do a post-mortem and figure out how we can prevent the same accident from happening again. And crucially, the point of a post-mortem is to find the root cause — not to ground the entire fleet.”
lea.verou.me/blog/2026/polyf…
Lea Verou Dev Tweets retweeted
Loosely coupled extensible systems are key to a healthy platform.
Extensibility can enable platform growth independent of consensus approval, while supporting native implementation optimizations when available.
Many modern tools would not exist without the web's extensibility.
🔥 New blog post: In defense of polyfills
A highly influential spec editor expressed the opinion that polyfilling is harmful.
I beg to differ.
lea.verou.me/blog/2026/polyf…