🚀 New WebPerf Snippet published! Detects preload resource hints for scripts that use async or defer attributes. This is an anti-pattern that wastes bandwidth & can hurt performance by artificially elevating the priority of resources that should load at lower priority #WebPerf #WebPerfSnippet

🚀 New WebPerf Snippet published! Detects potential performance issues with `rel="prefetch"` resource hints by analyzing quantity, size, type, and appropriateness of prefetched resources. webperf-snippets.nucliweb.net/Loading/Pref... #WebPerf #WebPerfSnippet #PerfTools

Here's your friendly reminder that CSS selectors are global and evaluated RTL, so if you have selectors that are very broad like `.container > div` you might be impacting performance in a measurable way 🙈 Before and after profile of server switching after some selector optimizations in @discord.com

@nolanlawson.com’s talk from PerfNow a few years back is well worth a watch — covers some of the selector performance issues along with the optimisations browsers have introduced nolanlawson.com/2023/01/17/m...

Excited to share my latest contribution to the Web Performance Calendar 2025! In this post, I dive into using Chrome DevTools for debugging web performance, with tips to help you speed up your sites and improve user experience. #WebPerf #Performance #DevTools #PerfTools

Debugging web performance with Chrome DevTools. @nucliweb.net shows how to triage big assets in Network, read CrUX live Core Web Vitals, and use Performance Insights and traces to improve LCP, CLS, and INP. #performance #devtools #chrome calendar.perfplanet.com/2025/chrome-...

Been loving NVIDIA's NeMo models recently to complement Whisper for transcription, but the startup felt a bit heavy. So I went on a profiling adventure! github.com/NVIDIA-NeMo/... Turned out to be fruitful… stoked to land a big optimization in NeMO. github.com/NVIDIA-NeMo/...

My talk at @henrihelvetica.bsky.social's SPDY meetup in Toronto is live: www.youtube.com/watch?v=xq2c.... It's pretty rough and unpolished, but I included some fun stories of the history of performance work in Chrome which you likely can't find anywhere else. Slides: docs.google.com/presentation...

The 2025 Web Almanac by HTTP Archive has been officially released! 🚀 We would like to thank all of our contributors from around the globe who made this extensive report possible! Check out the full report here: almanac.httparchive.org

Happy New Year! Join us next Thursday, January 15, "Frameworks for humans in the age of machines" with Rich Harris - @rich-harris.dev PLEASE update your RSVPs if you cannot attend! RSVP: www.meetup.com/web-performa... This is a joint event with @sveltesociety.dev NYC #webperf #wpo #perfmatters

I’ve decided to invest time in learning WebAssembly with the aim of improving the performance of some products I know that WebAssembly isn’t a silver bullet that solves everything, but there are use cases where it can significantly improve a product’s UX #WebPerf #WebAssembly #Performance

When web performance degrades, the impact is immediate. Conversions drop. UX suffers. SEO follows. The problem? These issues are often detected too late.

📣 Nuevo post: Chrome DevTools para depurar el rendimiento de una web Una guía paso a paso de cómo utilizo Chrome DevTools para detectar problemas de Web Performance en una web, así como validar algunas hipótesis joanleon.dev/posts/chrome... #WebPerf #DevTools

🚀 WebPerf Snippets – Major Update ✨ What’s new • Visual ratings 🟢/🟡/🔴 • Clean tables report • Automatic summaries • Issue detection with actionable recommendations • Improved docs with causes, fixes & official links 👉 webperf-snippets.nucliweb.net #WebPerf #CoreWebVitals #JavaScript #DevTools

⚡Featured posts this week: ✨Why Your Server Is Paying for Your CSS: David Lewis ✨Nuxt Scripts for improved Perf and Sec: @jacobandrewsky.bsky.social ✨Chasing BFCache navigations: Nicolas Hodin ✨TTFB doesn’t mean what you think: @programmingart.bsky.social 🙏Special thanks to the authors! #webperf

Lots of great stuff in this year's Perf Planet Advent/December series: calendar.perfplanet.com/2025/

Web Performance Calendar day 27 with @nucliweb.net on using Chrome DevTools for fun and profit: inspect heavy files in Network panel, monitor Core Web Vitals, record performance traces, validate optimizations, and more. calendar.perfplanet.com/2025/chrome-...

La propiedad CSS content-visibility puede mejorar significativamente el rendimiento de renderizado, especialmente en páginas con mucho contenido En este post: cómo funciona, un caso real con métricas antes/después, y snippets para auditar joanleon.dev/posts/conten... #WebPerf #Performance #CSS

Happy Holidays! Join us on January 15 — "Frameworks for humans in the age of machines" with Rich Harris - @rich-harris.dev RSVP now: www.meetup.com/web-performa... Rich is the creator of svelte.dev and rollupjs.org This is a joint event with @sveltesociety.dev NYC #webperf #wpo #perfmatters

How to load CSS (fast) calendar.perfplanet.com/2025/how-to-... by @yoavweiss #WebPerf #CSSPerf #Performance #CSS

Why Your Server Is Paying for Your CSS Choices dp-lewis.medium.com/why-your-ser... #CSS #WebPerf #ServerPerf

⚡Featured posts this week: ✨ LCP and INP are now Baseline: @tunetheweb.com @mmocny.com ✨ Faster pages with Compression Dictionaries: @karlijnlowik.bsky.social ✨ A Short History of Perf Engineering: Alex Podelko ✨ Next.js Perf Optimization: Dany Paredes 🙏 Special thanks to the authors! #webperf

Updated de Content-Visibility snippet for Chrome DevTools - Detects existing content-visibility usage - Finds offscreen optimization opportunities - CLS warnings for missing contain-intrinsic-size - Configurable thresholds webperf-snippets.nucliweb.net/Loading/Cont... #WebPerf #PerfTools

Web Performance Calendar day 18 with Amrik Malhans on breaking down LCP to pinpoint what's slowing down the page exactly and where to focus your UX-optimizing efforts calendar.perfplanet.com/2025/the-ana...

I ❤️ writing these annual wrap-up posts. From broad browser support for key metrics to nuanced metrics for diagnosing issues, 2025 has been filled with huge wins — not just for @speedcurve.com but for our entire #webperf community. Go, us! www.speedcurve.com/blog/2025-we...

Major update to the CSS Media Queries Analysis Snippet with a Performance Impact Analyzer It calculates the REAL cost of desktop-only CSS on mobile: 📉 Core Web Vitals Impact 💰 Estimated Conversion Lift e.g.: Fixing 30KB of unused CSS 180ms faster load and up to 1.8% conversion boost

I really love the page transition on PerfPlanet’s Calendar 🤩 Smooth details like this make a big difference in web performance and UX. #WebPerf #PerfPlanet #UX

🤩We just opened the Public Preview of our Reporting as a Service (RaaS) platform before the general release. Users from different countries are already accessing their personal Boards. Explore the platform by getting your own report: 👉 webperformancereport.com #webperf

Half a year ago, I published a pretty long paper about JPEG XL: arxiv.org/abs/2506.05987 I am happy to see that section 11.1 is already outdated!

Web Performance Calendar day 5 when @myshov.bsky.social shows us how to move heavy image decoding off the main thread. Drawing images in <canvas> freezing your UI and causing long tasks? Not anymore! calendar.perfplanet.com/2025/non-blo...

Speculation Rules on touch devices (where there's no hover) is a hard problem but it sounds like Chrome's making some good progress? htmhell.dev/adventcalend...

- Use a <picture> tag for semantic HTML - Sure, I’ll do it #SendMeCoffee 🫠

chrome-devtools-mcp v0.11.0 🎉 Features - emulation: add geolocation emulation tool - integrate DevTools issues into the console tools - support --user-data-dir github.com/ChromeDevToo... #DevTools #mcp #ai #Chrome

📣 New WebPerf Snippet Analyze all @media rules in CSS to identify classes and properties targeting viewports bigger than a specified breakpoint. Results are grouped by inline CSS and external files, with byte size estimates for potential mobile savings. #WebPerfSnippets #WebPerf

Análisis de Media Queries en CSS para Optimizar el Rendimiento joanleon.dev/posts/analis... 🇬🇧 version in thread #WebPerf #CSS #WebPerfSnippets #PerfTools #DevTools

📣 Updated my Resource Hints snippet for @chromedevtools.bsky.social Now detects common mistakes like: ❌ <link rel="preconnect dns-prefetch"> ❌ Non-standard rel values Perfect for auditing preload, prefetch, preconnect, etc webperf-snippets.nucliweb.net/Loading/Reso... #WebPerf #PerfTools

With @chromedevtools.bsky.social, we can streamline Web Performance Debugging with the help of the AI assistant #WebPerf #PerfTools #PerfDebugging

Dr. @guaca.bsky.social explains the diagnosis with @debugbear.com of our symptoms at DevFest Barcelona 2025 #DevFestBCN2025 #WebPerf #PerfTools #DevFest

Nuevo post "Más Allá de INP: LCP y el 90% invisible del rendimiento" de la serie de Long Animation frames API (LoAF) joanleon.dev/posts/loaf/m... #WebPerf #Performance #LoAF #LCP #CoreWebVitals

Effectively Monitoring Web Performance www.smashingmagazine.com/2025/11/effe... by @mattzeunert.com #WebPerf #Performance

I've updated the WebPerf Snippet "Find non Lazy Loaded Images outside of the viewport" to list images without loading="lazy". Now it shows: - Total number of images - Total file size - Individual details: URL, resolution & file size #WebPerf #WebPerfSnippets #PerfTools

Dark mode = On

Obs.js: context-aware web performance for everyone csswizardry.com/Obs.js/demo/ by @csswizardry.com #WebPerf #PerfTools #Performance #WebPerfSnippets

Our free HTML size analyzer can tell you what's taking up space in your HTML! Identify embedded images, fonts, or JavaScript hydration state. www.debugbear.com/html-size-an...

I reached peak performance using @chromedevtools.bsky.social's Performance panel! #DevBadges developers.google.com/profile/badg...

Chrome 143 will start rolling out today (most users get it next week). It includes a new set of options for your webperf traces — including saving sources & source maps: developer.chrome.com/docs/devtool... This makes it easier for those viewing traces outside of the page load to get more context.

AI assistance for performance developer.chrome.com/docs/devtool... by @matthiasrohmer.bsky.social #WebPerf #Performance #PerfTools #AI #PerfAI

Do you know the Web Performance Working Group? The mission of the Web Performance Working Group is to provide methods to measure aspects of application performance of user agent features and APIs. www.w3.org/webperf/ #WebPerf #Performance

HTML parsing speed depends a lot on how powerful the device that's visiting the website is. When I measure parse time on my laptop it takes under 7 milliseconds to process one megabyte of HTML. But on a low-end Android phone it takes 88 milliseconds! www.debugbear.com/blog/html-pa...

Quina il•lució em fa participar al #DevFest Girona 2025 ☺️ #GironaDevFest2025