How to use Website Speed Test
- Give Website Speed Test 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 lays out for you.
About this tool
Website Speed Test is a static, client-side tool with no backend. Website Speed Test reads a Lighthouse or PageSpeed Insights JSON report in your browser and surfaces the headline numbers without a server.
Because Website Speed Test parses a report you provide, the results match whatever run you exported. Your input never leaves the page, and no account or install is required.
Frequently asked questions
What does Website Speed Test do?
Use Website Speed Test to check your input without installing anything; everything happens client-side.
Do I need an account for Website Speed Test?
No — Website Speed Test needs no account, sign-up or installation.
Where is my data processed by Website Speed Test?
Entirely in your browser — Website Speed Test keeps your data on your own machine and sends nothing anywhere.
What file does Website Speed Test read?
Export a Lighthouse or PageSpeed Insights JSON report and load it into Website Speed Test; it surfaces the scores and Core Web Vitals locally.
Does Website Speed Test work offline?
Once the page has loaded, Website Speed Test keeps working with no network connection.