UX Rating: How many of your users are having a good time?
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It’s the simplest question you can ask about a website, and most performance tools can’t answer it directly.
Lighthouse tells you if a page, tested in a lab, is well-built. APM tells you your servers are healthy. CrUX monitoring shows Google SEO ranking liabilities. All useful signals.
But, sometimes, you need to take a step back and ask:
How many of my users are having a good time on our site right now?
This question matters to your business. Visitors who have a bad time bounce, abandon their carts, churn, and forget all about you. When people have a good time, they convert at a much higher rate, and become return customers.
UX Rating answers that question.
What UX Rating measures#
UX Rating is built from what your visitors actually felt. Every real user session reports up to four measurements: how quickly the main content arrived, how stable the layout stayed, how fast the page answered a tap, and how long the server took to respond.
Each of those measurements is graded Good, Needs Improvement or Poor against Google’s thresholds. UX Rating pools every grade from every session and shows you the share that came back Good.
That is a sharper number than a headcount of happy customers. One slow interaction doesn’t write off an otherwise good visit, and a session that was slow on all four measures counts against you four times. You see how much of the experience you delivered was good, not how many people scraped a pass.
Lots of performance tools have a UX Rating like metric, but UX Rating in Calibre is the gold standard. Two things set it apart.
- Calibre RUM samples by user sessions, not just pageviews. It grades the experience of an actual person moving through your site.
- User experiences that feel slow or unstable are captured and recorded towards your UX Rating. Using Core Web Vitals and Time to First Byte (TTFB).
Every grade in your UX Rating is a delay somebody actually sat through, which makes it a faithful assessment of user experience rather than an estimate of one.
You can use UX Rating as a high-level health check, approximation of passing Core Web Vitals, and a way of locating problematic areas of your site.
Once you know you have a problem, you can use other specialised metrics to understand what is happening, and identify in-page elements that are hurting you most.
Why Good UX percentage is the number to watch#
Knowing how much of your real-world experience is good is a powerful insight.
"Only 30% of what our visitors experienced was good" prompts action in a way that an LCP value or a Lighthouse score doesn’t and can’t. It is stated in terms anyone can act on: how the site felt to the people using it.
You can see, at a glance, how much of the experience you deliver is good and how much of it is driving people away. That directness brings focus. Focus moves the number.
Where UX Rating immediately paid off for Calibre#
A few weeks ago, our own UX Rating took a sharp dive. This isn’t a bit, it really happened.
Following changes to the website, our Good UX share dropped from 85% to just 34%. Close to two thirds of everything we measured from real visitors came back below good. That is not a handful of unlucky sessions, that is most of the experience our site was delivering.
From our Audience report, we could immediately see what had happened. An update to our free Core Web Vitals Test had missed an important cache header. Every request was flowing straight-through our CDN, smashing the origin server.
Because the pages draw a lot of traffic, overall performance dipped as the server was busy processing requests. One missed header created a site-wide liability.
The Audience report automatically segments by Page Grouping, which pointed straight at a cluster of high-traffic dynamic pages: /tools/core-web-vitals-test/*.
We found and fixed the missing cache header. UX Ratings improved rapidly. A simple mistake does not have to be a big deal, and in this case, it wasn’t.
Since then, we’ve also used UX Rating to pinpoint other substandard areas of our site and improve them. All based on actual human experience.
Successful high-level metrics point the flashlight, and that’s exactly what UX Rating does.
UX Ratings create alignment and cut-through jargon#
UX Rating provides clarity that can bring everyone together with a shared understanding. There’s something for everyone:
- Designers can uncover bumpy or frustrating user experiences to inform future design choices and implementation details that need polish.
- Developers get a single signal that catches regressions and segments cleanly by page grouping, devices, and geography.
- Product leaders and management get a number that survives standups, retros and review sessions without the need for translation.
- SEO and marketers get a metric that tracks Core Web Vitals, which Google uses for search ranking, and gets to understand full user experience journeys.
- Owners and executives get a top-line metric that provides context to NPS, retention, and conversion metrics.
Put user experience in focus#
If you’re not looking at your site this way yet, you can start today.
Calibre customers can find UX Rating across the Sites list, the RUM Dashboard, Pages and Audience reports, and the CrUX Dashboard, Pages and Audience reports. Since June 2026, it is also the headline number on our free Core Web Vitals Test and in Compare Website Speed, so you can check it without an account.
If you’re not a Calibre user, sign up for a free trial and check it out or learn more about UX Rating in our docs. It’s the best way to get a quick pulse on how your users are doing.