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🇺🇸 Experts in web performance, we help you to solve performance issues

🇪🇸 Expertos en web performance, te ayudamos a solucionar problemas de rendimiento

https://perf.reviews/
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We Improve Your Website's Performance

Increase your revenue and make your users happier with our web auditing and optimization services

👉 perf.reviews/en

#WebPerf #Performance #PerfReviews
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🚀 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
February 11, 2026 at 3:27 PM
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🚀 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
Prefetch Resource Validation | WebPerf Snippets
A curated list of snippets to get Web Performance metrics to use in the browser console or as snippets on Chrome DevTools by Joan León
webperf-snippets.nucliweb.net
February 16, 2026 at 3:00 PM
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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
January 27, 2026 at 4:41 PM
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@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...
My talk on CSS runtime performance
A few months ago, I gave a talk on CSS performance at performance.now in Amsterdam. The recording is available online: (You can also read the slides.) This is one of my favorite talks I’ve ev…
nolanlawson.com
January 28, 2026 at 9:36 AM
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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
February 2, 2026 at 9:22 AM
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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-...
January 7, 2026 at 12:00 PM
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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/...
January 10, 2026 at 10:10 PM
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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...
How To Get Your Boss To Let You Work On Web Performance, by Rick Byers of Google.
YouTube video by Henri Helvetica
www.youtube.com
January 20, 2026 at 3:53 PM
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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
January 16, 2026 at 3:00 AM
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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
Frameworks for humans in the age of machines - Rich Harris, Thu, Jan 15, 2026, 6:00 PM | Meetup
**Svelte** turns **10 this year** — an eon in web development. After so much time, and at a moment when engineers are increasingly outsourcing the work to agents, is there
www.meetup.com
January 8, 2026 at 3:13 PM
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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
January 8, 2026 at 3:08 PM
When web performance degrades, the impact is immediate.

Conversions drop. UX suffers. SEO follows.

The problem? These issues are often detected too late.
January 5, 2026 at 9:36 AM
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📣 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
Chrome DevTools para depurar el rendimiento de una web | Joan León
Una guía paso a paso de cómo utilizo Google Chrome DevTools para detectar problemas de Web Performance en una web, y validar algunas hipótesis para solventarlos.
joanleon.dev
January 2, 2026 at 11:58 AM
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🚀 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
WebPerf Snippets | WebPerf Snippets
A curated list of snippets to get Web Performance metrics to use in the browser console or as snippets on Chrome DevTools by Joan León
webperf-snippets.nucliweb.net
January 2, 2026 at 7:56 AM
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⚡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
December 28, 2025 at 12:10 PM
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Lots of great stuff in this year's Perf Planet Advent/December series:

calendar.perfplanet.com/2025/
December 28, 2025 at 3:39 AM
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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-...
Chrome DevTools for Debugging Web Performance
This is a step-by-step guide on how I use Chrome DevTools (DevTools from now on) to detect Web Performance issues on a website, as well as validate hypotheses to fix some of the problems found. Discl...
calendar.perfplanet.com
December 27, 2025 at 2:47 PM
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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
Optimiza el renderizado con content-visibility | Joan León
La propiedad CSS content-visibility mejora el rendimiento de renderizado. Caso práctico con métricas y snippets para detectar oportunidades.
joanleon.dev
December 27, 2025 at 11:25 AM
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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
Frameworks for humans in the age of machines - Rich Harris, Thu, Jan 15, 2026, 6:00 PM | Meetup
**Svelte** turns **10 this year** — an eon in web development. After so much time, and at a moment when engineers are increasingly outsourcing the work to agents, is there
www.meetup.com
December 22, 2025 at 6:49 PM
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Reposted by PerfReviews
⚡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
December 21, 2025 at 1:27 PM
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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
Content Visibility – Nextra
A curated list of snippets to get Web Performance metrics to use in the browser console or as snippets on Chrome DevTools by Joan León
webperf-snippets.nucliweb.net
December 20, 2025 at 12:41 AM
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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...
The Anatomy of LCP - A Deep Dive into Sub-Parts
Optimizing LCP (Largest Contentful Paint) is not just reducing the file size of your images, there's a lot more that goes into optimizing the loading strategy - and you can only grasp where the bottle...
calendar.perfplanet.com
December 18, 2025 at 11:37 PM
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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...
SpeedCurve | 2025 was a big year! Here are some highlights...
From broad browser support for key metrics to nuanced metrics for diagnosing issues, 2025 has been filled with wins.
www.speedcurve.com
December 18, 2025 at 10:29 PM