Thank you so much @veneman.dev 🥰
Two awesome new stickers on my laptop from a great project: @projectwallace.com
@nucliweb.net
Joan León
@nucliweb.net
⚡️ Web Performance Artisan at @perf.reviews | Google Dev Expert in Web Tech | Cloudinary Ambassador | ❤️ Image Optimization | Girona
@nucliweb.net
@foolip.orgReposted by @nucliweb.netJPEG XL shipped in Chrome 155 today, try it out!
Huge kudos to Luca and team for getting this done. Image codecs are cool in so many levels, and I'm super impressed by the people who make that magic happen.
@nucliweb.netDuring a perf audit for a client, I read this in a PR: "The module should only be loaded once, not every time a file is selected." When I read it, something didn't add up, so I started digging. And the result surprised me.
I wrote a post joanleon.dev/en/dynamic-i...
@nucliweb.netI don’t turn single outliers into tests. Tests come from segments with volume: p75 device, connection and the top paths by traffic. Outliers go to investigation first; if the pattern repeats across sessions, then it earns a test.
@nucliweb.net100%. The goal is lab tests that look like real users: same devices, same conditions, same paths. The MCP is making that loop really fast.
@benschwarz.bsky.socialReposted by @nucliweb.netHow far ahead browsers fetch lazy images: • Chrome: 1,250px on 4G, 2,500px on 3G, 6,000px (!!) on 2G • Firefox: 600px, on any connection • Safari: one viewport. Lazy iframes: 0px, they wait until on screen
@nucliweb.netOne thing I’m experimenting with for a performance audit:
Using RUM data + @debugbear.com MCP to build synthetic tests based on how the product is actually used
RUM → real user behaviour → MCP → representative synthetic tests
@nucliweb.netAnd thanks to @carlesnunez.bsky.social too for the @framer.com sticker ☺️
@nucliweb.netThank you to @en.sitnik.es for the @evilmartians.com sticker ☺️
@nucliweb.netThe case against JPEG XL
Investigating JPEG XL's place as a Web image codec, by @giannirosato.com, via @webperfreport.bsky.social
@nucliweb.netI added WebMCP to the GeeksCAT Conf 2026 website, so an agent can ask for the schedule, the speakers or the event details as tools instead of reading the HTML.
It's a static Astro site, so I go through it layer by layer.
@developer.chrome.comReposted by @nucliweb.netWe created Modern Web Guidance to bring web platform expertise right into your agent workflows. Have you tried pairing these skills with Chrome DevTools for agents to audit performance and automatically fix code?
Check it out and join 10K+ web developers who are coding smarter → goo.gle/4yEVz1h
@nucliweb.netP75 is green: LCP 1.58s, INP 176ms, CLS 0.01. P90: LCP 2.68s, INP 352ms, CLS 0.17. 15% of visits get a noticeably worse experience.
Product Performance doesn't end once you pass CrUX: if P75 is good, work on P90.
@webperfreport.bsky.socialReposted by @nucliweb.net⚡Featured posts this week:
✨ Submit your proposals for Interop 2027: @rachelandrew.co.uk
✨ Reading a performance profile: @nucliweb.net
✨ HTML over WebSockets: @androsfenollosa.bsky.social
✨ Intro to Web UX and Speed Optimization: @sergeyche.dev
🙏 Special thanks to the authors!
#webperf
@tomayac.comReposted by @nucliweb.net🤩 Fantastic article by @nucliweb.net on HTTP cache partitioning and the #CrossOriginStorage API: joanleon.dev/en/http-cach.... Try the embedded demos with the COS extension installed or in one of the experimental browser builds (see the Awesome Cross-Origin Storage list: github.com/tomayac/awes...).
@nucliweb.netSoftware is evolving fast.
My focus hasn’t changed: helping teams improve performance, UX, and conversion
AI generates working code faster than ever… but not optimized for performance
That’s where we add value: from “it works” to “it’s excellent”
Reading @addyosmani.bsky.social’s new book
@nucliweb.netA collection of handy resources for understanding font performance on the web, by @mandymichael.bsky.social
github.comGitHub - mandymichael/font-performance-resources: A collection of handy resources for understanding font performance on the webA collection of handy resources for understanding font performance on the web - mandymichael/font-performance-resources