How to use Mobile Site Speed Test
- Add a Lighthouse JSON report (or paste it) to Mobile Site Speed Test to get started.
- Click Read report — Mobile Site Speed Test processes everything on your device.
- Read the category scores and Core Web Vitals that Mobile Site Speed Test lays out for you.
About this tool
Mobile Site Speed Test is a static, client-side tool with no backend. Export a report from Chrome DevTools or PageSpeed Insights and load the JSON into Mobile Site Speed Test to see the scores locally.
Because Mobile Site Speed Test parses a report you provide, the results match whatever run you exported. It behaves the same on desktop and mobile, with nothing stored remotely.
Frequently asked questions
What does Mobile Site Speed Test do?
Use Mobile Site Speed Test to check your input without installing anything; everything happens client-side.
Does Mobile Site Speed Test cost anything?
No — Mobile Site Speed Test is completely free, with no sign-up and no hidden limits.
Is my input private in Mobile Site Speed Test?
Yes — your input never leaves your device; Mobile Site Speed Test does all the work in your browser.
What file does Mobile Site Speed Test read?
Export a Lighthouse or PageSpeed Insights JSON report and load it into Mobile Site Speed Test; it surfaces the scores and Core Web Vitals locally.
Does Mobile Site Speed Test work on mobile?
Yes — Mobile Site Speed Test is just a web page and runs on any modern browser, including phones and tablets.