Why this tool is useful
Use this checker to confirm whether the browser is presenting near 60, 120, 144 or another refresh cadence after changing monitor or operating-system settings.
Browser & Privacy · runs locally
Monitor Refresh Rate Checker
Estimate the active tab's animation cadence from requestAnimationFrame timestamps and report median FPS, frame interval and timing variation.
Ready. Your working data stays in this browser.
How it works
The page samples consecutive requestAnimationFrame timestamps for a short bounded interval, removes the first warm-up frames and calculates median and average cadence locally.
Practical example
Run the checker in a visible foreground tab. A 120 Hz display commonly produces a median interval near 8.33 ms, while a 60 Hz display is near 16.67 ms.
Validation
The calculation is deterministic and explains validation errors instead of silently changing invalid input.
Privacy boundary
Input and output remain in this tab. Copy and download happen through browser APIs without a server upload.
Result passport
Every run reports its tool mode, timestamp and input/output size so transformed data can be audited.