KlyveroRefresh Rate Test
Estimate rendering cadence from observed frame samples.
RequestAnimationFrame measures browser callback cadence, not physical panel refresh. Fullscreen is optional. If unavailable, expanded view keeps browser controls visible. Use the exit button or Escape to leave.
Observed browser callback cadence is not certified panel refresh rate; throttling/VRR/multiple displays affect it
How to use this test
- Keep the page visible and choose Measure for 5 seconds.
- Keep the tab in the foreground and avoid changing zoom or moving displays during a sample.
- Read the reported browser observation and its limitations. Retry after any interruption.
Checks included in this tool
FPS Test
Observe animation FPS and frame-time variation. These are this page’s animation callbacks, not a counter for another game or app. Long intervals describe delivered frame timing without identifying a hardware fault.
- Measure a foreground sample and review the average and long frame intervals.
- Keep the tab in the foreground and avoid changing zoom or moving displays during a sample.
- Read the reported browser observation and its limitations. Retry after any interruption.
Animation callback samples only; no panel scanout or general game FPS
How it works & what results mean
How the test works
Estimate rendering cadence from observed frame samples. It uses requestAnimationFrame; performance.now. The workspace shows observations from this browser or asks for your own confirmation.
Understanding your result
The estimate comes from real animation callbacks. Browser scheduling, load, power saving and variable refresh can make callback cadence differ from panel specification. Observed browser callback cadence is not certified panel refresh rate; throttling/VRR/multiple displays affect it Missing data, blocked permission and an operation that could not run are shown separately. None establishes a hardware fault.
Keep checking
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About this test & common questions
how to estimate refresh rate online?
Run a refresh rate test to observe browser frame cadence and an approximate FPS reading. Keep the page visible while samples are collected.
can a browser measure exact monitor Hz?
Animation timing is a browser proxy affected by scheduling and display settings; it is not a certified monitor Hz measurement.