Refresh Rate Test
Measures your display's refresh rate from the timing of requestAnimationFrame callbacks in the browser you're using. Measurement starts as soon as the page opens and shows the closest standard value such as 60Hz, 120Hz or 144Hz. To check for stuck pixels or uneven color, use the Dead Pixel Test; for screen size and DPR, try the Screen Size & Viewport Checker.
🔒 Runs in your browser · Your data is never sent to a server
Measured rate
Measuring…Hz
Closest standard rate:-
Status: Measuring
Detailed statistics
| Samples | - |
| Frame interval (median) | - |
| Frame interval (average) | - |
| Shortest interval | - |
| Longest interval | - |
| Rate from the average | - |
| Interval jitter (std. deviation) | - |
| Dropped frames (over 1.5x median) | - |
How to use
- Measurement starts automatically when the page opens. Wait a few seconds for the value to settle.
- The closest standard rate, such as 60Hz, 120Hz or 144Hz, is shown.
- Press "Reset" to measure again.
Notes
- This measures the browser's paint timing, so power-saving or battery-saver modes in the OS or browser may cap it below your display's real rate (for example at 60Hz).
- With multiple monitors, the value is for the monitor this window is on. Move the window and measure again.
- On variable refresh rate displays (G-SYNC, FreeSync, ProMotion, etc.) the rate changes with content and load, so it may not match a standard value.
- Heavy load from other tabs or apps can cause dropped frames, giving a lower value or large jitter.
- Browser behavior means the measurement can be off by a few percent.
Glossary
Refresh rate
How many times per second the screen updates its image, in Hz. A 60Hz display updates 60 times a second and a 144Hz display 144 times; higher values make motion look smoother.
requestAnimationFrame
A browser API that calls your code just before the next screen update. It is normally synced to the display refresh rate, so the interval between calls reveals the rate.
Variable refresh rate (VRR)
A technology that changes the display update interval dynamically to match the GPU frame rate, such as G-SYNC, FreeSync and ProMotion, reducing tearing and stutter.
FAQ
My monitor is 144Hz but it shows 60Hz.
The OS display setting may still be at 60Hz, the cable or port (e.g. an older HDMI standard) may not support the higher rate, or a power-saving mode may be capping it. Check your OS settings and connection.
Why is the value slightly off, like 59.9Hz or 143.8Hz?
Many "60Hz" standards are really 59.94Hz, and measurement adds an error of a few percent. The tool shows the closest standard rate within tolerance as "Closest standard rate".
The value is unstable and jumps around.
On variable refresh rate (VRR) displays the value changes with load. Heavy load from other tabs or apps also causes dropped frames and noisy readings, so close other work, press Reset and measure again.
Can I measure a phone?
Yes. Note that with battery saver on, even a 120Hz-capable phone may be limited to 60Hz. Turn power-saving mode off before measuring.
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