Refresh Rate Test
Measures your display's actual refresh rate using requestAnimationFrame timing. Works on any browser, any OS, no extensions needed.
Initialising
Sampling...
--Hz
Detecting panel rate...
0/10
Last 30 samples (Hz)
Measurement Details
| Last sample | -- |
| Rounded spec | -- |
| Confidence | -- |
| Method | requestAnimationFrame timing |
| Browser | -- |
How it works
Request frames
We call requestAnimationFrame in a loop. The browser fires callbacks at its native refresh rate.
Measure deltas
Each callback receives a high-resolution timestamp. We compute 1000 / (t2 - t1) to get instantaneous Hz.
Filter outliers
GC pauses and tab-switching produce spikes. We discard samples outside 2 standard deviations and use a rolling median.
Snap to spec
Once 10 consecutive samples agree within 3Hz, we round to the nearest standard panel rate (60/90/120/144/165/240).
Bought 120Hz but seeing 60Hz?
Your panel might be running at a lower rate. Common causes:
- Windows Display Settings → Advanced display → refresh rate set to 60Hz
- HDMI 1.4 cable (caps out at 60Hz above 1080p) — try DisplayPort or HDMI 2.1
- GPU driver forcing V-Sync at a lower rate
- Laptop on battery (power-saving mode caps refresh rate)
- Browser hardware acceleration disabled (check chrome://gpu)