How to use Free Site Speed Test
- Give Free Site Speed Test a Lighthouse JSON report (or paste it) to work from.
- Click Read report — Free Site Speed Test processes everything on your device.
- Use the category scores and Core Web Vitals Free Site Speed Test produces — nothing was uploaded.
About this tool
There is no server behind Free Site Speed Test. Free Site Speed Test reads a Lighthouse or PageSpeed Insights JSON report in your browser and surfaces the headline numbers without a server.
Because Free Site 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 is Free Site Speed Test for?
Free Site Speed Test runs entirely on your device: add your input, and it checks it locally in real time.
Is Free Site Speed Test free to use?
Yes — Free Site Speed Test is completely free, with no usage limits.
Does Free Site Speed Test upload my data?
No — Free Site Speed Test processes everything locally in your browser, so nothing you enter is uploaded or stored.
What file does Free Site Speed Test read?
Export a Lighthouse or PageSpeed Insights JSON report and load it into Free Site Speed Test; it surfaces the scores and Core Web Vitals locally.
Does Free Site Speed Test work on mobile?
Yes — Free Site Speed Test is just a web page and runs on any modern browser, including phones and tablets.