Third-party scripts work fine in tests but cause real user pain: Analytics blocking rendering Chat widgets slowing interactions Payment lag RUM catches this. https://requestmetrics.com/web-performance/you-need-rum-to-understand-web-perf/ #WebPerf #ThirdParty

Complete performance strategy: 🧪 Synthetic testing in development 👥 RUM in production 🔍 Investigate with synthetic ✅ Validate with RUM https://requestmetrics.com/web-performance/you-need-rum-to-understand-web-perf/ #WebPerf #WebDev

Gmail scores terribly on Lighthouse despite being one of the snappiest web apps ever built. Context matters for performance measurement. https://requestmetrics.com/web-performance/you-need-rum-to-understand-web-perf/ #WebDev #Performance

Synthetic testing: "Your site loads in 1.2 seconds! 🎉" Real users: "This page is taking forever..." 😤 RUM bridges this gap. https://requestmetrics.com/web-performance/you-need-rum-to-understand-web-perf/ #WebPerf #UserExperience

Performance issues only RUM can catch: 🔍 Device-specific problems 🌍 Geographic gaps 💰 Traffic spike disasters 📱 Progressive degradation https://requestmetrics.com/web-performance/you-need-rum-to-understand-web-perf/ #WebPerf #RealUserMonitoring

Lighthouse simulates an "85th percentile user" but their simulation is usually wrong for your audience. RUM shows you YOUR users' reality. https://requestmetrics.com/web-performance/you-need-rum-to-understand-web-perf/ #WebDev #Performance

Chrome User Experience Report is like the lite beer of Real User Monitoring 🍺 Better than nothing, but lacks the substance you need for real decisions. https://requestmetrics.com/web-performance/you-need-rum-to-understand-web-perf/ #WebPerf #CoreWebVitals

Your CDN looks great in tests but European users get 3x slower load times. Your checkout tests perfectly but mobile users abandon carts due to lag. This is why you need RUM. https://requestmetrics.com/web-performance/you-need-rum-to-understand-web-perf/ #WebPerf #UX

That moment when your Lighthouse score is 💯 but users are still complaining about slow pages... Stop guessing, start measuring what they actually experience. https://requestmetrics.com/web-performance/you-need-rum-to-understand-web-perf/ #WebDev #Performance

🚨 Plot twist: 50% of websites with perfect Lighthouse scores still fail Core Web Vitals for real users. Your synthetic tests run in a perfect bubble. Your users live in the real world. https://requestmetrics.com/web-performance/you-need-rum-to-understand-web-perf/ #WebPerf #RealUserMonitoring

Jordan Griffin discusses lowering the barrier to getting user feedback during the redesign of ⁨TrackJS⁩ . youtube.com/shorts/e4URn... Learn more about the TrackJS redesign 👇 trackjs.com/blog/a-fresh...

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Discover why Time to First Byte (TTFB) is crucial for website speed in this essential Concepts of Web Performance tutorial with @toddhgardner.com from Request Metrics.

Master the art of loading JavaScript efficiently in this essential Concepts of Web Performance tutorial with @toddhgardner.com from Request Metrics. youtu.be/vS3-1RQecEE

@duffeh.bsky.social wrote about focusing on the experience of your real users instead of SEO for web performance. He quoted my work on Keyword Vitals that it might not matter for your keywords. https://iankduffy.com/articles/web-performance---prioritising-user-experience-ahead-of-search-rankings/

David Jacobs at Axos Bank uses Request Metrics to make their websites fast and usable. "The engineering team behind this make Request Metrics an incredible value. I cannot recommend enough."

🔀 The powerful but dangerous Vary header: Vary: Accept-Encoding This creates separate cache entries for gzipped vs uncompressed content. But be careful - Vary on dynamic headers can destroy cache effectiveness 💣 requestmetrics.com/web-performance/http-caching/

The Image Optimization Hack Nobody Talks About 🎩 💡 Optimize your thumbnails! ✅ Resize before serving (don’t rely on CSS) ✅ Convert to WebP/AVIF ✅ Serve from a CDN or separate subdomain More image tricks: https://requestmetrics.com/web-performance/high-performance-images/ #WebDev #Optimization

💥 Cache busting 101: styles.d41d8cd98f.css vs styles.css?v=1.2 Both methods invalidate cache when content changes, but the first (filename hashing) is far superior! It enables longer cache times without refresh issues 🔒 requestmetrics.com/web-performance/http-caching/

🔄 "no-cache" ≠ "don't cache"! This actually means "cache but validate before using" - not "don't cache at all" (that's no-store). This confusion causes so many performance issues! 🤦‍♂️ requestmetrics.com/web-performance/http-caching/

@joshuaclareflagg.bsky.social uses Request Metrics for his #ecommerce stores to give him Quick and Easy insights into his #CoreWebVitals, and how to make his website faster!

Your hero image is probably your LCP element. If it’s slow, your SEO suffers. ✅ Compress it (WebP/AVIF) ✅ Use fetchpriority="high" ✅ Serve via CDN Fix LCP now: https://requestmetrics.com/web-performance/high-performance-images/ #SEO #LCP

WebP vs. AVIF: Which One Wins? 🏆 WebP & AVIF crush file sizes, but which is better? ✅ WebP: Smaller than JPG/PNG, widely supported ✅ AVIF: Even smaller, but not universal Best practice? Serve both with <picture>. Full guide: https://requestmetrics.com/web-performance/high-performance-images/

Lab Scores only represent 🧑‍💻a single load 🌎 from a single location ⏰ and a single point in time. Generally, the score doesn't matter-- user experience matters. And you measure that with RUM and CrUX. So why should you trust the numbers from Request Metrics? Because we SHOW OUR WORK!

Stop Hosting Images on Your Server 📦 Serving images from your main server? That’s a performance disaster. CDNs cache images worldwide for faster delivery & lower bandwidth. Move your images to a CDN like Bunny. More tips: https://requestmetrics.com/web-performance/high-performance-images/

🏷️ ETag: the unsung hero of HTTP caching ETag: "123abc987654" This simple fingerprint header tells browsers when content hasn't changed, enabling 304 responses that send zero data but keep content fresh 🧠 requestmetrics.com/web-performance/http-caching/

Bad animations kill performance. Stick to transform & opacity—they run on the GPU and won’t block frames. 🚀 More tips here: 🔗 https://requestmetrics.com/web-performance/long-animation-frame-loaf/ #webperf #perfmatters

📄 Perfect caching for HTML documents: Cache-Control: public, max-age=300, must-revalidate Short cache time means content updates quickly, while "must-revalidate" ensures browsers double-check before showing potentially stale content 🔄 requestmetrics.com/web-performance/http-caching/

Don't make users download images twice 🛑 Browsers shouldn’t download the same images every visit! Set Cache-Control headers so users store images locally: Cache-Control: public, max-age=31536000, immutable Full caching guide: https://requestmetrics.com/web-performance/http-caching/ #Caching

🚀 The optimal way to cache your static assets: This tells browsers "don't even check if this file has changed" - cutting unnecessary validation requests and dramatically improving load times 💨 requestmetrics.com/web-performance/http-caching/

Responsive Images: Right Size, Right Device 📱 Stop serving massive images to small screens! Use srcset to send the right size image based on device width. Less bandwidth = faster load times. Learn how: https://requestmetrics.com/web-performance/high-performance-images/ #WebDev #Performance

JavaScript can ruin your site’s smoothness. If it runs too long, it blocks frames and causes lag. Optimize your scripts and let the browser breathe. 🏃‍♂️ Full guide: 🔗 https://requestmetrics.com/web-performance/long-animation-frame-loaf/ #webperf #perfmatters

Why HTTP/3 Speeds Up Image Delivery 🚀 Your images aren’t slow—your protocol is. HTTP/3 reduces latency, speeds up image loading, and boosts mobile performance. Still on HTTP/2? You’re missing out. Learn why HTTP/3 matters: https://requestmetrics.com/web-performance/http3-is-fast/ #CDN #WebDev

Think your site feels slow but don’t know why? Long Animation Frames (LoAFs) might be the culprit. Use Chrome DevTools → Rendering → FPS meter to find them! 🔎 Full guide: 🔗 https://requestmetrics.com/web-performance/long-animation-frame-loaf/ #webperf #corewebvitals

Do you ❤️ Request Metrics? We need your help! We just listed on @slashdot.org and our reviews look sad 😢 Give us a hand and let us know what you think by sharing a review! sourceforge.net/software/pro...

Website images without width & height cause layout shifts, especially lazy-loaded ones! Set dimensions so the browser reserves space. <img src="" height="100" width="100" /> Fix CLS issues fast: https://requestmetrics.com/web-performance/high-performance-images/ #CLS #WebPerf

The web runs at 60 FPS (ideally), meaning each frame has 16ms to do its thing. If your code takes longer, it lags. 🎢 Fixing Long Animation Frames (LoAFs) keeps your UI snappy! More on hitting that smooth 16ms target: 🔗 https://requestmetrics.com/web-performance/long-animation-frame-loaf/

The main thread is like a one-lane highway. 🚗💨 If you block it with slow code, everything stops. Fixing LoAFs frees up the road so your site stays smooth. Learn how to unclog your site: 🔗 https://requestmetrics.com/web-performance/long-animation-frame-loaf/ #webperf #seo

🔥 Loading every image on page load? That’s killing your performance. Use lazy-loading to load images only when needed: <img src="..." loading="lazy"> More lazy-loading tricks 👉 https://requestmetrics.com/web-performance/high-performance-images/

Picking the wrong photo format kills performance! JPG for photos, PNG for graphics, WebP/AVIF for modern compression. Choosing wisely cuts file sizes in half! Full breakdown: https://requestmetrics.com/web-performance/high-performance-images/ #WebPerf #CoreWebVitals

Does WebPerf actually matter for SEO? If you missed my talk at PerformanceObserver, here's the video! Check out what we discovered with Keyword Vitals: https://www.youtube.com/watch?v=s7PhpumaU78

LoAFs happen when your code hogs the main thread. Too many calculations? Rendering too much? Blocking interactions? 🚧 Fix it, and your site will feel 1000x smoother. Full breakdown: 🔗 https://requestmetrics.com/web-performance/long-animation-frame-loaf/ #perfmatters #corewebvitals

🚨 Stop serving massive images to mobile users! Your 2800px-wide hero image is wasting bandwidth and slowing down smaller screens. Use srcset & sizes to deliver the right image for each device. Full guide 👉 https://requestmetrics.com/web-performance/high-performance-images/

Keyword Vitals shows you how web performance impacts your SEO rankings by analyzing real-world Core Web Vitals data directly in Google search results. requestmetrics.com/resources/to... by @toddhgardner.com #WebPerf #Performance #SEO

🗓️ TODAY at 5:00 UTC Our founder @toddhgardner shares his investigation into whether #webperf actually matters for #SEO in 2025. Join the free online meetup at https://performanceobserver.dev/

The new Lab Scan email is 🔥 We automatically scan your busiest pages, rollup your scores and common issues from Mobile and Desktop, and show details from your slowest pages. Why are you still manually scanning your website?

Ever tapped a button and nothing happened? That’s a Long Animation Frame (LoAF) messing with your smooth experience. LoAFs are the hidden lag spikes of the web! 🔥 Learn why they suck and how to fix them: 🔗 https://requestmetrics.com/web-performance/long-animation-frame-loaf/ #webperf

Picking the wrong image format kills performance! JPG for photos, PNG for graphics, WebP/AVIF for modern compression. Choosing wisely cuts file sizes in half! Full breakdown: https://requestmetrics.com/web-performance/high-performance-images/ #WebPerf #CoreWebVitals

Vector images (SVG) scale infinitely, stay crisp at any size, and have tiny file sizes—perfect for icons, logos, and graphics. Ditch PNGs when you can! Just don’t export a PNG as SVG—that’s cheating. 😉 Full breakdown here: 👉 https://requestmetrics.com/web-performance/high-performance-images/

Vector images (SVG) scale infinitely, stay crisp at any size, and have tiny file sizes—perfect for icons, logos, and graphics. Ditch PNGs when you can! Just don’t export a PNG as SVG—that’s cheating. 😉 Full breakdown here: 👉 https://requestmetrics.com/web-performance/high-performance-images/