Measuring refresh rate
The test automatically measures how many frames per second your browser draws. This normally matches your monitor's configured refresh rate. If it shows 60 Hz although you own a 144 Hz or 240 Hz monitor, the higher rate usually isn't enabled.
Monitor stuck at 60 Hz? Change it here
- Windows 11: Settings → System → Display → Advanced display → “Choose a refresh rate”.
- Windows 10: Settings → System → Display → Advanced display settings → Refresh rate.
- macOS: System Settings → Displays → Refresh rate.
- NVIDIA / AMD: you can also pick the rate in your graphics driver's control panel.
Use the right cable
High refresh rates at high resolutions need enough bandwidth. An old HDMI 1.4 cable only manages 60–75 Hz at 1440p. Use DisplayPort 1.4 or HDMI 2.1 and plug into the graphics card, not the motherboard.
Measurement notes
- Keep the tab in the foreground and close other heavy apps.
- With multiple monitors, the browser measures the screen the window is on.
- Safari caps some pages at 60 Hz, even on ProMotion displays. Use Chrome, Edge or Firefox for an accurate reading.
- Laptops in power-saving mode often lower the refresh rate automatically.
Dead pixel test
The pixel test fills the whole screen with one solid color after another. Look carefully for anything unusual:
| Defect | Visible on | Meaning |
|---|---|---|
| Dead pixel | White, red, green, blue | Always black, usually permanent |
| Stuck pixel | Black | Always lit in one color, often fixable |
| Backlight bleeding | Black (dark room) | Bright edges or patches, caused by the panel design |
Stuck pixels can sometimes be revived with rapidly changing colors or gentle pressure with a soft cloth while the monitor is off. New monitors with pixel defects can be returned within the return window; how many defects the warranty covers depends on the manufacturer's pixel policy (ISO 9241-307 class).