Slides Hyvä Developers Paradise 2026
Sunshine, coding, webperformance and knowing your Core Web Vitals issues without clicking? What a life!
Blog
Introducing Health Checks: automatically diagnose your Core Web Vitals issues
Health Checks analyze your real user data and turn it into clear, actionable insights. Instead of spending time hunting for performance issues yourself, RUMvision now finds them for you. Spend less time hunting and more time fixing issues.
Launch RUMvision 2.0 - the future of RUM is here!
Super proud moment, RUMvision 2.0 is LIVE 🎉 It has taken a lot of hard work, a lot of talking, and - most importantly - a lot of listening to our clients. But this new version truly puts the "vision" into RUM. Let us tell you what we've build and how it can help your business.
Meet Karlijn Löwik, the one who makes it make sense
Karlijn is the person who translates web performance into something everyone can understand. She's CEO and co-founder of RUMvision, co-chair of the W3C RUM Community Group, board member of Mage-OS NL, and the one who coined SUX (Sitespeed User Experience). Because good SUX sells.She speaks at conferences across the world, sits at the table with Google and other browser vendors, and runs a company with her husband. She also spent this morning vacuuming the office before this interview.
Meet Roderik Derksen, the business strategist behind RUMvision
Roderik is the one thinking three steps ahead, turning technical possibilities into business models. He’s our co-founder and oversees business development, business administration, partnerships, and marketing strategy, but you probably won’t see him on stage or in your inbox. Next to RUMvision, he’s been running his own marketing company since 2009.
What's coming with RUMvision 2.0?
We’re launching a new version of RUMvision. Our 2.0 model is a rebuilt foundation with new features we’ve been working on for months. Here’s what that means for you.
No-Vary-Search: fixing cache-breaking tracking parameters
Tracking parameters are useful for marketing attribution, but they quietly introduce a caching problem across the web. Browsers treat URLs with different query parameters as separate resources, even when the underlying page content is identical.
Meet Jordy Scholing, the guy you’ll probably talk to first at RUMvision
I’m the co-owner, manage customer success, and the person you’ll probably talk to first when you start using RUMvision. But did you know: four years ago, I was selling organic tea from home?
Why 1 in 4 of your customers think your site is slow - even if you pass Core Web Vitals
Your ad clicks are landing on slow pages. Your first-time visitors are bouncing. And your Core Web Vitals dashboard isn't showing you any of this - let's dive into the world beyond the 75th percentile. And not make it a snoozefest.
Smaller payloads and faster pages with Compression Dictionaries
Web performance improvements often come from small, incremental gains. Better caching, fewer requests, smaller files. Every once in a while though, a new platform feature shows up that makes you pause and think: why has this not been mainstream already?
RUMvision 2025 -wrapped
What fun is being a Real User Monitoring tool if you can't pull up real data and wrap it - 2025 style! Worst third-parties, silliest faces (including Jordy's ill-advised moustache) most occuring platforms + countries in our dataset and MUCH more
140× faster RUMvision dashboards with new Elastic setup
The story behind our migration with real-world benchmarking, reindexing 8.3 billion documents, our collaboration with Elastic, and the 20 to 140× speed gains our users now experience.
Prerender Until Script: in between Prefetch and Prerender
Speculative loading is one of the few techniques that can fundamentally change how fast a website feels. And a new kid on the block got introduced: prerender_until_script
9 quick wins in UX and pagespeed for BF/CM
Black Friday is just around the corner! What can you do to make sure your users experience is optimal? Allow us to share 9 quick-wins to make sure you do not miss out on conversions or brand loyalty in the long run. Almost no coding required!
How fast is fast enough - Meet Magento Netherlands 2025
Eight lessons learned from rumming thousands of Magento shops. Like setting you all a challenge to aim for the 90th percentile, speculation rules rule, use-cases and.. a sneak preview into RUMvision 2.0!
Safari catching up: both INP and LCP support in their 26.2 release
The WebKit team has rolled out a notable change in the 26.2 beta with support for two major performance APIs. This update moves Safari significantly closer to full Core Web Vitals support.
SyliusCon 2025 in Lyon
At Friday 17th of October, the 4th edition of SyliusCon took place. I travelled to Lyon to give a talk on Core Web Vitals debugging via DevTools.
Firefox ships support for INP metric
Mozilla Firefox has just shipped support for Interaction to Next Paint (INP), one of Google’s Core Web Vitals metrics focused on responsiveness. This is great news for anyone monitoring site speed and user experience.
SEO Benelux 2025
At Friday October 10th, the second edition of SEO Benelux took place. I travelled to Antwerp to talk about different sitespeed tools.
Ciao Rome! Meet Magento Italy 2025 slides
All roads lead to Rome, but it was our first time giving a talk in Italy. And it was a great succes! Want to find the slides, read about our Baseline integration, the Zitmaxx use case or how to improve webperformance for Hyvä, you find al the resources here.