Refresh Rate Test
Test your monitor refresh rate online in Hz: detect 60Hz, 120Hz, 144Hz, 240Hz and 360Hz displays, measure frame time pacing, jitter and dropped frames.
🔒 Runs entirely in your browser — nothing is uploadedHow to test your monitor refresh rate online
Whether you just purchased a high-refresh-rate gaming monitor, bought a new laptop with a 120Hz ProMotion display, or want to verify that your HDMI or DisplayPort connection is operating at full speed, this online refresh rate tester detects your screen's hardware refresh rate in real time without installing third-party utilities.
The test measures the cadence of requestAnimationFrame rendering loops using the high-resolution
performance.now() timer. Because the browser's graphics engine synchronizes frame callbacks directly with
your monitor's vertical blanking interval (V-Sync), the frequency of these redraws matches your active display rate:
60 Hz (16.67 ms per frame), 75 Hz (13.33 ms), 120 Hz (8.33 ms), 144 Hz (6.94 ms), 165 Hz (6.06 ms), 240 Hz (4.17 ms),
or 360 Hz (2.78 ms).
Understanding frame pacing, jitter, and micro-stutter
High refresh rate gaming is not just about raw Hertz; consistent frame delivery is equally crucial. Even on a 240 Hz monitor, if frame delivery times oscillate between 2 ms and 15 ms, you will experience noticeable visual stutter.
The live frame pacing graph plots the delivery interval of every recent frame:
- Ideal Frame Time: Calculated as
1000 / Hz. A stable monitor produces a near-flat horizontal line matching this expected target. - Frame Jitter: The statistical standard deviation of frame delivery times. Low jitter (< 0.8 ms) indicates flawless synchronization between your operating system compositor, GPU, and monitor.
- Dropped Frames: Spikes where a frame took more than 1.6× the expected duration, causing a dropped render cycle and perceptible micro-stutter.
Troubleshooting monitors locked at 60 Hz
It is surprisingly common for users to buy a 144 Hz or 240 Hz gaming display and inadvertently run it at 60 Hz for months. To unlock your monitor's full potential:
- Windows Display Settings: Right-click the desktop → Display settings → Advanced display. Ensure the Choose a refresh rate dropdown is set to your panel's rated maximum (e.g., 144 Hz or 240 Hz).
- Check Cable Bandwidth: Older HDMI 1.4 cables and basic adapters cap 1440p and 4K displays at 60 Hz. Use a DisplayPort 1.4 or HDMI 2.1 cable connected directly to your dedicated GPU rather than the motherboard port.
- Browser Hardware Acceleration: Confirm that hardware acceleration is enabled in your browser settings so the browser compositor utilizes your GPU's full rendering pipeline.
How to use
- Keep this tab focusedBrowsers throttle background tabs to 1–10 Hz to save battery. Keep this window active in the foreground for an accurate reading.
- Observe the live Hz detectionThe tester samples consecutive presentation timestamps via requestAnimationFrame to detect your monitor's true refresh rate.
- Review frame time metricsCheck your average frame delivery time (e.g. 16.67 ms for 60 Hz, 6.94 ms for 144 Hz) and frame jitter variance.
- Inspect the smoothness barTrack the high-speed motion bar with your eyes to inspect motion clarity and check for skipped frames or tearing.
- Troubleshoot display settingsIf a 144 Hz or 240 Hz monitor only displays 60 Hz, check your Windows Display Settings or macOS Refresh Rate dropdown.