How fast is your website, really?
Enter a URL and we load your page in a real browser, up to eight times: three cold runs each on emulated mobile and desktop, plus a repeat visit per profile. You get Core Web Vitals, page weight, third-party cost, and the fixes, worst first.
Loads the page up to eight times in a real browser; slow pages shorten the run budget. Usually 30 to 60 seconds. Nothing stored.
What this measures
Real browser, real loads
No estimates: headless Chromium loads your page cold, three runs per profile, and the report shows the median.
Core Web Vitals
LCP, CLS, and total blocking time, measured the way Google defines them, against the official thresholds.
Mobile and desktop
Mobile runs on an emulated 9 Mbit/s connection with a 4× slower CPU, because that is where pages actually fail.
Where the bytes go
Page weight, request count, and which third-party scripts cost the most, plus the concrete fix for each finding.
Slow pages lose leads
We fix performance at the source: caching and server setup, image pipelines, third-party cleanup, and frontends that pass Core Web Vitals.
Questions about the Website Speed Check
How is this different from PageSpeed Insights?
PageSpeed Insights runs one Lighthouse load per click. This check loads the page up to three times cold on mobile and on desktop, each run in a fresh browser, and reports the median, so one lucky or unlucky run does not decide the score. It also lists the heaviest requests and the third-party scripts by cost.
What are the Core Web Vitals thresholds?
Google rates Largest Contentful Paint as good at 2.5 seconds or less, Cumulative Layout Shift at 0.1 or less, and Interaction to Next Paint at 200 milliseconds or less. A lab test cannot interact like a visitor, so this check reports total blocking time as the stand-in for interactivity, as Lighthouse does.
Why is my mobile score lower than desktop?
The mobile runs emulate a 9 Mbit/s connection with 150 ms latency and a CPU four times slower than the test machine, close to a mid-range phone. That is where heavy JavaScript and oversized images cost the most.
How is the overall score calculated?
Each profile gets a weighted score from 0 to 100 based on the Core Web Vitals and loading metrics. The overall score counts mobile at 60 percent and desktop at 40 percent.
Why do results vary between runs?
Server response time, ad auctions, third-party scripts, and CDN caches change from load to load. The median of several cold runs removes most of that noise, and the repeat visit per profile shows what browser caching saves.
From the blog
- The best free website speed tests, ranked
A vendor-neutral ranking of the best free website speed tests: what each one measures, why lab and field scores disagree, and which fixes matter.
