How to use Website Speed Test Free
- Give Website Speed Test Free a Lighthouse JSON report (or paste it) to work from.
- Press Read report to run it locally in your browser.
- Read the category scores and Core Web Vitals that Website Speed Test Free lays out for you.
About this tool
Website Speed Test Free runs entirely in your browser. Export a report from Chrome DevTools or PageSpeed Insights and load the JSON into Website Speed Test Free to see the scores locally.
It shows category scores and Core Web Vitals such as LCP, CLS and TBT, read straight from the JSON. It behaves the same on desktop and mobile, with nothing stored remotely.
Frequently asked questions
What is Website Speed Test Free for?
Website Speed Test Free runs entirely on your device: add your input, and it checks it locally in real time.
Do I need an account for Website Speed Test Free?
No — Website Speed Test Free needs no account, sign-up or installation.
Is my input private in Website Speed Test Free?
Yes — your input never leaves your device; Website Speed Test Free does all the work in your browser.
What file does Website Speed Test Free read?
Export a Lighthouse or PageSpeed Insights JSON report and load it into Website Speed Test Free; it surfaces the scores and Core Web Vitals locally.
Does Website Speed Test Free work offline?
Once the page has loaded, Website Speed Test Free keeps working with no network connection.