Free tools
Page Speed Test
Type an address. Our browser opens it on a phone-sized screen and times everything: the score, the vitals, the weight, and every single request.
How to use it
- Open the Page Speed Test under Tools and enter any public https address.
- Press Test now and stay on the page. A real browser is opening your address right now, usually for under half a minute.
- Read the Summary tab first: the Tarsier score, the four vitals, and the ranked fix list. Open the Waterfall tab for every request and the Details tab for weight by kind and heaviest hosts.
How the score works
The Tarsier score starts at 100 and loses points for measured problems: a late largest paint, blocked first paint, slow first byte, layout shift, heavy pages, and crowded request counts. 85 and up is Quick, 50 and up is Heavy, below that is Slow.
What it measures
- Largest Contentful Paint, First Contentful Paint, and layout shift.
- Time to first byte, request count, and byte weight split by script, style, image, and font.
- Third-party hosts and DOM size.
- A screenshot of the page as tested, in a phone-sized viewport.
Lab load only. The test opens the page once without scrolling or clicking, so interaction metrics are not measured and never invented.
Limits
Five free runs a day per visitor, https pages only. Tarsier customers get the same timing every day on all 50 sites, automatically.