Screen Refresh Rate Detector
Detect 60Hz, 120Hz, 144Hz via rAF
Click to run timing test.
📚 Learn more — how it works, FAQ & guide Click to expand
Learn more — how it works, FAQ & guide
Click to expand
Screen Refresh Rate Detector
Detect actual browser refresh rate via requestAnimationFrame timing. Verify your 120Hz / 144Hz / 240Hz monitor is really running at advertised speed in this browser context.
How to use this tool
- 1
Click Run
5-second precise rAF timing analysis.
- 2
See Hz
Detected rate + frame consistency.
- 3
Verify
Compare to advertised monitor spec.
Frequently Asked Questions
Why might my 144Hz monitor show 60Hz?
Display setting in OS, not just monitor capability. macOS often defaults to 60Hz even on ProMotion. Windows: Display Settings → Advanced → set 144Hz. Some HDMI cables max at 60Hz.
How accurate is the detection?
requestAnimationFrame fires at ≤display rate. After 300+ frames the average converges to true Hz ±0.5. Power-saving mode and other browser tabs can throttle below true rate.
Why does Chrome cap at 60Hz sometimes?
Battery saver, low power mode, or background tab throttling. Foreground tab + plugged in = full rate. Brave/Edge similar.
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100% Privacy. This tool runs entirely in your browser. Your data is never uploaded to any server.