Joan León 🏞️⚡️

In 2023 I published WebPerf Snippets as a website, with snippets to paste into the DevTools console Version 2.0 is also built for AI agents: every snippet returns the same structured result, so an agent reads data instead of console logs 🧵 #WebPerf #AI

RT @addyosmani:

RT @yoavweiss: If you ever struggled with understanding if your CSS performance issues are coming from style calculation or from layout, LoAF's styleDuration and layoutDuration is shipping in Chromium 158 to help with that

RT @WebPerfReport: ⚡Featured posts this week: ✨ Todays PHP Security Release: @ThePHPF ✨ Shopify Checkout Hijack Attack: @romanzipp ✨ AI, make the website good: @zachleat ✨ Whats new in the W3C WDS: @studio24 🙏 Special thanks to the authors! #webperf

RT @tunetheweb: Experimental soft navigation data now available in CrUX!! If your site is an SPA then see how your own Core Web Vitals data will change at: And read this blog post for more details about how Core Web Vitals change in general:

RT @miriamgonp: Since March I’ve been building tools with Claude to understand my own tumor. Now Anthropic is supporting it with $30,000 in credits 🥹 I wrote everything I built. What I need now is someone who can make a personalized vaccine, and a hospital that can give it 💜 👇

Anthropic gave me $30,000 in Claude credits to research my own tumor I wrote what I built since March. I’m looking for someone who can manufacture a personalized vaccine, and a hospital that can give it

RT @sarah_edo: We have presents for you! 🎁 - A new WebMCP Skill with best practices for security, development, & consequential flows - WebMCP Types: TypeScript definitions, with type inference from InputSchema Give em to your agent, it helps scaffold out WebMCP so fresh and so clean clean

RT @WebPerfReport: 🎉 WebPerformance Report Week #42 is out! ✅ Join our growing community: ⚡ Performance Report 🛡️ Security Report ♿ Accessibility Report 📊 Analytic Report 🔎 SEO Report Explore our report catalog 👉 #webperf #websecurity #a11y #analytics #seo #ai

RT @GDGGirona: From population models to personalized AI! How can we build digital twins tailored to individuals? Join #GDGGirona on Oct 22 for a live demo exploring generative deep learning, transfer learning & personalized healthcare 👉 #AI #MachineLearning

Also new: 17 interactive demos, the browser support of each snippet, and a DevTools extension in beta.

And a new domain: If you try it, I'd like to hear what's missing

RT @mattzeunert: Google's CrUX data now includes more nuanced Core Web Vitals metrics for single page apps! You can check the new soft navigation metrics in our website speed test here:

RT @ChromiumDev: The Split View API is here! Arriving in Chrome 155 and developed in close collaboration with Mozilla and browser vendors in the WebExtensions Community Group, this API integrates directly into the browser.tabs namespace without requiring any extra manifest permissions →

Es todo un lujo poder formar parte de @a11y_conf como ponente, donde hablaré de "El árbol de accesibilidad frágil: por qué el HTML semántico es clave para el rendimiento web" 🎟️ Aprovecha ahora que quedan entradas!!! #a11y #WebPerf #a11yConf

RT @WebPerfReport: 🎉 WebPerformance Report Week #41 is out! ✅ Join our growing community: ⚡ Performance Report 🛡️ Security Report ♿ Accessibility Report 📊 Analytic Report 🔎 SEO Report Explore our report catalog 👉 #webperf #websecurity #a11y #analytics #seo #ai

During 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 #JS #WebPerf

RT @WebPerfReport: ⚡Featured posts this week: ✨ Improving site perf by shipping more CSS: @__joshblack ✨ How AI Agents Use Websites: @giacomozecchini ✨ Chasing the Perfect Website: Morgan Murrah ✨ Perf at Scale with Ryan Townsend: @RyanTownsend 🙏 Special thanks to the authors! #webperf