Joan León 🏞️⚡️

I have published a website with Web Performance Snippets to make it more user-friendly, more orderly, and with a search feature ⚡️💾 webperf-snippets.nucliweb.net #WebPerf #Performance #PerfTools

Versión en castellano joanleon.dev/posts/trailing…

I can't visit a site without opening DevTools. On skills.addy.ie, every internal click fired a 301 redirect: a full round trip before the page even started to load. The cause, and the one-line Astro fix: joanleon.dev/en/trailing-sl… #WebPerf #Astro #Netlify

I'm testing the @DebugBear MCP with Claude Code, and my first impression is that combining DebugBear's great tools with the power of AI Agents is awesome for creating executive and detailed technical reports... and if you have the opportunity to run it on the source code, the potential is impressive. I'll write a post with my experience and thoughts. #WebPerf #PerfTools #AI #WebPerfAI

@carlesnunez This post was published by an AI agent 🤖

The final AI detector “—“

Integrating AI into web apps usually means relying on constant network availability for server-side inference, adding latency and data-handling round-trips. Chrome's built-in AI APIs let you run models locally using hardware acceleration. Deliver on-device summarization, structured JSON prompting, and translation entirely offline with zero network overhead → goo.gle/3SfFGP5

WebPerformance Report Week #25 is out!✅ Our first early users have started receiving their GA4 Analytics Reports. Subscribe: ⚡Performance: webperformancereport.com 🛡️Security: webperformancereport.com/httpo ♿A11y: webperformancereport.com/wave 📊Analytics: DM us for early access #webperf

@nabaroa Me encantaría conocer los cambios, guarda muchos traces, que luego los podrás comparar

@nucliweb tenía esto en guardados... y me he puesto a leerlo más detenidamente y creo que me vendrá de perlas para nuestras landings. Ya te contaré. 😀

La propiedad CSS content-visibility puede mejorar significativamente el rendimiento de renderizado, especialmente en páginas con mucho contenido. En este artículo explico cómo funciona, muestro un caso real con métricas antes/después, y comparto dos snippets para auditar su uso en cualquier web. joanleon.dev/posts/content-… #WebPerf #Performance #CSS

A few weeks ago I noticed that Linear got slower than it used to. Especially on the new Diffs feature, that we were getting ready to release, it was pretty bad. For days I was running profiles, staring at profiles, bisecting with agents from every direction. The pattern was clear - we accessed the DOM a ton, which blocked the main threads on style recalcs and layout for 10s or 100s of milliseconds over and over. I shipped dozens of PRs to get rid of those layout-causing calls, using pretext and whatever tricks the agents and I could come up with. It helped, but only a bit. I was getting desperate.

We just published a new blog post benchmarking page speed for train booking websites in Europe! We also looked at the technical factors that drive the results, and how these websites could be optimized. debugbear.com/blog/which-eur…

@DebugBear Renfe 🙈

The YAML frontmatter in @antigravity Skills has 5 fields that change everything: kind, model, temperature, max_turns, and tools. Google hasn't documented them officially yet. I've been testing them in real projects and wrote up what each one does. joanleon.dev/en/antigravity… #AI #AgentSkills #Gemini #Antigravity

May brought big updates to the web platform: You can now use native lazy loading for video and audio elements to easily save bandwidth and boost performance. Plus, CSS name-only container queries are Baseline newly available, simplifying your code → goo.gle/4dWV8qn

Stop struggling with AI coding tools that don't know the modern web. Modern Web Guidance codifies decades of Chrome's web platform expertise into your coding agents. Get expert-vetted skills for high-level disciplines and low-level features, with fallback strategies informed by Baseline data for reliable cross-browser support → goo.gle/4on8BMS

It seems that I get very intense when I talk about Web Performance 😂 Photo of last week’s talk in the @commitconf

49 snippets de Web Performance que se pegan en la consola de DevTools y te dicen por qué tu web va lenta. Cero instalación, cero dashboards, cero esperar al reporte de Lighthouse. Lo mantiene @nucliweb (Joan León), GDE en Web Tech y Cloudinary Ambassador. 1.4k stars en GitHub. 🧵

The WebMCP origin trial is now available in Chrome 149 → goo.gle/4x97wMK Sign up to integrate experimental features for live testing and help shape future iterations of the API. Build structured tools so agents can complete tasks accurately without guessing your UI.