Example
At 60 frames per second, the average interval is about 16.7 ms. A 95th-percentile interval much higher than the median indicates occasional slower frames during this test.
How it works
The page draws a controlled number of simple shapes to a small canvas and records requestAnimationFrame intervals. It stops at the selected duration, when you press Stop, or when the tab is hidden. The report is computed locally.
Frequently asked questions
Does this tell me my monitor refresh rate?
No. It measures frames delivered to this page by the browser. It cannot certify the physical display refresh rate.
Why does the result change between runs?
Browser scheduling, device power settings, other tabs, thermal limits and the selected drawing workload can change frame delivery.
Is this the FPS I will get in a game?
No. Games use different engines and workloads. This is a small browser-only comparison, not a game benchmark.
Limits and accuracy
Use realistic values. The tool explains assumptions and does not replace professional, official or safety advice where that applies.