SpeedCurve

SpeedCurve has been acquired by @embrace.io! We’re combining forces to connect performance, reliability and UX across web and mobile apps. And yes, our team and tools will remain the same. 😀 Our founder @markzeman.com shares how our 12-year journey led us here: www.speedcurve.com/blog/perform...

So excited to be paired with @paulcalvano.bsky.social for this double-header on PerformanceObserver next week! Paul will take a deep dive into the HTTP Archive. Then I'll break down the "performance plateau" – why you need to know it and how to find it. performanceobserver.dev/events/episo...

In our rush to align page speed with SEO and business metrics, have we in the #webperf community lost our way? In this post, based on the keynote I gave at #PerfNow a few months ago, I explore how it's not too late to bridge the gap between pragmatism and user delight. www.speedcurve.com/blog/fast/

ICYMI, here's a wrap-up of exciting #webperf and #ux highlights from 2025! ⭐ Broad browser support for LCP and INP (W👀T!) ⭐ New metrics & visuals for measuring user happiness ⭐ Deeper metrics for JS diagnostics ⭐ Better budgets = easier regression-fighting www.speedcurve.com/blog/2025-we...

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...

If you only have time to do ONE THING to make your site holiday-ready (so you can relax and enjoy the next few days off) it's this: CREATE PERFORMANCE BUDGETS 😀 No code changes required 😀 Literally takes just 1-2 minutes 😀 You get alerts if your pages slow down 👉 www.speedcurve.com/web-performa...

🚨 New EMA Impact Brief: Embrace + @speedcurve.com is a big step forward for modern #observability. Together they deliver deeper user context, unified mobile + web + synthetic visibility, and an OTel-first foundation built for AI-ready reliability. Read more ➔ ow.ly/tsXY50XxcpZ

What happens when observability merges with front-end performance monitoring? You get the best of all worlds — performance, reliability, and UX across web and mobile! Join our founder @markzeman.com, CPO @cliffcrocker.bsky.social, and @embrace.io President Andrew Tunall on December 9 to learn more!

Unoptimized images are STILL a common problem, and they hurt things like: 🙁 #A11y 🙁 #webperf and #UX metrics like LCP and CLS 🙁 Conversions 🙁 #SEO 🙁 Sustainability I'll be talking about this (and solutions!) today (12:15pm PT / 3:15pm ET) at #PixelPalooza. Get your FREE ticket: lnkd.in/g_N8YFrs

Third parties represent a MASSIVE potential single point of failure for your site. 1. AUDIT & remove unused tags 2. DEFER or load asynchronously 3. TRACK scripts & create #webperf budgets 4. KNOW your SLAs with vendors 5. CREATE a playbook for failures 👉 www.speedcurve.com/web-performa... #ux

🎄 Holiday Readiness Tip 7: Track your CDN! CDN performance can be a black box. Did you know you can track CDN health using Server Timing headers? 👉 How to get backend transparency from your CDN: www.speedcurve.com/blog/server-... 👉 More holiday readiness tips: www.speedcurve.com/blog/holiday...

#PixelPalooza is coming up this Thursday! This awesome FREE online event covers how to make sure all those helpful images and videos on your site don't hurt #webperf and #a11y. I'm joining @seancdavis.com to talk about the hidden cost of media on the web. Get your ticket 👉 cfe.dev/events/pixel...

Video of my @perfnow.nl keynote is up! In this talk, I challenged the false choice between magic and pragmatism. Don't settle for "fast enough". Instead, aim to create a user experience that's #pragmagical — blending user delight with measurable business impact. conffab.com/presentation...

I love heatmaps so much! They're the best way to get instant insight into where #webperf issues are lurking across your site. Taking it even further, you also get breakdowns across dimensions like page label, browser, device, and location. *chef's kiss* 👉 www.speedcurve.com/blog/new-hea...

Slides from my @perfnow.nl talk — How Fast Is Fast Enough? — are up! If you’re at #PerfNow (or even if you’re not) I’d love to talk about creating a delightful experience for your users. speakerdeck.com/tammyeverts/...

Sharing a few of the sources I cited during my #PerfNow talk, I’ll start with this one… Here’s a deeper dive into how to create correlation charts that help you see the relationship between performance metrics and business/engagement metrics. www.speedcurve.com/blog/site-sp...

Another source from my #PerfNow talk… Here’s why you need to know the performance plateau for your site. www.speedcurve.com/blog/web-per...

For #PerfNow folks who want to go even deeper on Long Animation Frames, @andydavies.me wrote the definitive guide. www.speedcurve.com/blog/guide-l...

Learn more about Total Blocking Duration (TBD), the experimental new metric that @andydavies.me is pioneering. #PerfNow www.speedcurve.com/blog/long-an...

Making Sense of Long Animation Frames… The slides from my #PerfNow talk are available on Notist noti.st/andydavies/9...

And last (but definitely not least) here’s @cliffcrocker.bsky.social’s super-interesting analysis of INP and its correlation with UX and business metrics. #PerfNow www.speedcurve.com/blog/INP-use...

We ❤️ making users happy! One of our customers (a large healthcare system) had this to say about our tools and service — including kudos to our amazing @cliffcrocker.bsky.social! 👉 Learn how we collaborate with you to build your #webperf and #ux practice: www.speedcurve.com/why/collabor...

Excessive JS is a UX monster. It hurts important metrics like LCP and INP, which in turn hurts bounce rate and conversion rate. I dug into this topic in a recent post, where I compared the #webperf of landing pages for well-known sites, from Apple to Uber. www.speedcurve.com/blog/campaig...

I've been exploring @speedcurve.com's new Vitals Overview dashboard with some customers for a week or so now, and all I can say is WOW. Not only is it fun to play with, it also halves the time it takes to investigate #webperf and #ux issues. 👉 Take a quick tour: www.speedcurve.com/blog/a-smart...

We just added @csswizardry.com to our Web Performance Heroes starter pack! (Yes, it's a bit late, but better late than never.) Every month, we honour a new hero and add them to this list. Follow along and meet the folks without whom the web would be a sadder and slower place. go.bsky.app/FTbRtFk

Every fall I hear so much FOMO from folks who missed @perfnow.nl. Don't let it happen to you! We have amazing speakers sharing the newest best practices for the #webperf topics you care about: AI, APIs, #a11y, CSS, JS, frameworks, tools, culture, workflows & more! Get your tickets soon! perfnow.nl

How fast is fast enough? I'll be exploring this question in my #PerfNow keynote. I hope to see you there! And if you have your own thoughts on this question, I'd love to hear them! #webperf #sitespeed #pagespeed #ux

Retail ad campaigns are $$$ — yet campaign landing pages are often the slowest pages on a site. That slowness has a direct impact on conversions. 💸 I tracked landing pages for 19 leading sites to see who's fast, who's slow, and what's causing their bottlenecks. www.speedcurve.com/blog/campaig...

Schedule schedule on the wall, who has the best line-up of them all? perfnow.nl/schedule.html

I recently started instrumenting both @cloudflare.social and browser cache hits/misses and the numbers, while obvious, are compelling. The best request is the one that never happens. Check that 0ms TTFB 😍 ℅ @speedcurve.com

Zero-second TTFB FTW! While a fast Time to First Byte doesn't mean your pages will deliver a fast user experience, a slow TTFB almost certainly guarantees your pages will deliver a slow UX. Learn more 👉👉👉 www.speedcurve.com/web-performa...

🔥 Quick page speed tip! Use critical CSS for faster rendering. Users will abandon a page if it seems empty and inactive for more than 3 seconds. If they see content rendering or the skeleton of a page loading, you'll buy more time and patience. 👉 Read the guide: www.speedcurve.com/web-performa...

Ever wonder why you get DIFFERENT NUMBERS for the SAME METRICS using different #webperf tools? 🕒 Synthetic vs synthetic? 🕕 Synthetic vs RUM? 🕘 RUM vs CruX? Here are some of the most common reasons. (The most important thing? Track changes within a single tool!) www.speedcurve.com/web-performa...

performance.now() is coming! @tammyeverts.com asks a seemingly-simple question: How Fast Is Fast Enough? She'll touch on questions — ranging from neuroscience to business metrics — to get you thinking about how you create, measure, and report your performance goals. perfnow.nl/speakers.htm...

Need help with web performance optimization? Have a tricky new build you're working on? I have two projects wrapping up and am available for new ones starting next week. sia.codes/services/

🩺 You don’t *have* to use Obs.js to adapt your site. You can use it as an analytics add-on and send data off to @speedcurve.com! csswizardry.com/Obs.js/demo/...

One of the fun things about taking holiday time is sitting back at my desk, looking at my monitor, and asking myself "What is it I do again?" If this sounds like you — and you care about site speed and UX — here's a quick refresher! 👉 👉 Web Performance Guide: www.speedcurve.com/web-performa...

So many great articles in this guide — all written by actual humans! (Shout-out to @andydavies.me, @cliffcrocker.bsky.social, @tkadlec.bsky.social, Joseph Wynn, @markzeman.com, and Steve Souders!)

New to the world of web performance? Welcome! Here's everything you need to know to master website monitoring, analytics, and diagnostics. Learn how to deliver a fast, joyous experience to all your users. www.speedcurve.com/web-performa... #webperf #pagespeed #sitespeed #ux #corewebvitals

"Synthetic, RUM, and CrUX data each have their place. It's important to keep in mind the limitations of each monitoring tool and what they're best used for so we don’t make the mistake of overlooking valuable insights." Excellent explainer from @markzeman.com: www.speedcurve.com/blog/crux-ru...

I used this to build a quick obfuscator. This will be great for anonymising @speedcurve.com dashboards before putting them in talks etc. Peep the address bar and tab name, too!

In today’s edition of “Guess That Unresponsive App”… Guess this app that would’ve been really helpful — and potentially lifesaving — to access when my family and I were hiking in the mountains yesterday… but which didn’t work because we were on 3G.

Loving the shift away from bloated client-side JavaScript. With RUM tools offering better visibility into the impact of JS, the DX vs. UX trade-off is becoming harder to ignore. Any UX focused changes in your stack making it to production? Did your numbers improve? www.speedcurve.com/blog/long-an...

Coming up in less than an hour – at 10am PDT / 1pm EDT! Henri and I will be chatting about page speed and UX, including the all-important question: How fast is fast enough?

✨ SPDY STREAM 007 ✨ @tammyeverts.com of @speedcurve.com has seen and helped shaped so much in performance. She's an author, conference fave and co-chair for the @perfnow.nl conference. Tammy will share insights you'll want to tune into. Join us! 📆 Wed Aug 13th ⏰ 1PM EDT 🔗 bit.ly/spdy-stream-007

Same code, same infrastructure, different context. Web performance is sometimes an ‘us thing’ and sometimes a ‘them thing’. For better or worse, we have a responsibility to cater to both.

Holy moly... our Speed Matters newsletter has gained 1K new subscribers in the past month! The summer edition goes out next week. It's not too late to sign up and join our 18K subscribers! Browse the archive and sign up here: www.speedcurve.com/newsletter/ (We won't spam you, I promise.)

I’m working with a client who has a very diverse (adverse?) customer base, so we’re sending off some more high fidelity Network and Device information to @speedcurve.com:

CrUX isn't new, but there's still confusion about what it is and when it's useful (and when it's not). This is a FANTASTIC post from @markzeman.com that breaks down the difference between synthetic, RUM, and CrUX data – and when and why to use each tool. www.speedcurve.com/blog/crux-ru... #webperf

"Should I use synthetic monitoring, real user monitoring, or CrUX?" @markzeman.com wrote this helpful post! It includes: 🟠 How synthetic and RUM work 🟠 What is CrUX? 🟠 Is CrUX a substitute for RUM? 🟠 When & why to use each tool 🧀 An obscure cheese metaphor www.speedcurve.com/blog/crux-ru...