Joan León Posts
All the articles I've posted.
WebPerf Snippets agent-first: structured returns and minimal tokens
Published:WebPerf Snippets scripts now return structured JSON directly from evaluate_script() and are minified at build time with dead code elimination, significantly reducing token footprint.
WebPerf Snippets and Agent SKILLs: deterministic audits with Chrome DevTools MCP
Published:WebPerf Snippets become Agent SKILLs with scripts as deterministic tools for AI agents, executable directly in the browser via Chrome DevTools MCP.
WebPerf Snippets + WebMCP: web metrics that AI understands
Published:WebPerf Snippets exposes its performance measurement tools via WebMCP, the new protocol that lets AI assistants interact with the browser natively.
WebAssembly: the W3C's forgotten standard
Published:WebAssembly has been a W3C standard since 2019, but many developers still don't know about it. What it really is, how it works, and why you should know about it.
SVGs on the web: performance comparison based on how you load them
Published:Inline, sprite with <use>, <object>, <img>... each way of loading an SVG has different implications for performance, caching and rendering. A practical analysis to help you choose well.
Practical guide to the <img> element: from the basics to LCP
Published:The <img> element has attributes that make a real difference in performance: loading, decoding, fetchpriority, srcset and sizes. A practical guide to using them well.
Yield to Main: setTimeout vs queueMicrotask vs scheduler.postTask
Published:A practical guide on how to use setTimeout, queueMicrotask and scheduler.postTask to break up long tasks and optimize INP. Comparison with measurable examples.
Optimizing Consent Scripts for Core Web Vitals
Published:Consent management scripts (CMP) compete with critical resources if not prioritized correctly. A server-side strategy to optimize loading based on visit type.