Monitor Refresh Rate Test

Monitor refresh rate is the number of times per second your display updates the image on screen, measured in Hertz (Hz). A 60 Hz monitor refreshes 60 times per second, while a 144 Hz monitor refreshes 144 times per second. Higher refresh rates produce smoother motion, reduce motion blur, and lower input lag — benefits most noticeable in fast-paced games and high-speed video content.

The test uses your browser's requestAnimationFrame API, which fires a callback synchronized to the display's vertical blank interval — the same moment the monitor refreshes its panel. By recording the timestamp of each callback and computing the time difference between frames (dt), we calculate Hz as 1000 / dt milliseconds. The test collects 120 frames, discards warmup frames, then computes the median refresh rate and standard deviation for a stable, accurate result.

Several factors can cause a lower-than-expected reading: (1) Your OS display settings may still be set to 60 Hz — check Settings > Display > Advanced Display Settings (Windows) or System Preferences > Displays (macOS). (2) Your cable may not support the monitor's full bandwidth — DisplayPort 1.4 and HDMI 2.1 are required for high refresh rates at 4K. (3) Your GPU driver may limit the rate — verify with NVIDIA Control Panel or AMD Radeon Software. (4) Browser hardware acceleration may be disabled — enable it in your browser's performance settings.

Standard deviation (Std Dev) measures how consistent your frame timing is. A low standard deviation (under ±1 Hz) means your frames are arriving at very regular intervals, indicating a stable, well-performing display and GPU. A higher standard deviation (±5 Hz or more) suggests frame timing inconsistency, which can cause visible stutter or screen tearing even if the average Hz is correct. Stability issues are often related to GPU load, V-Sync settings, or display driver problems.

The test works on all modern browsers that support requestAnimationFrame — Chrome, Firefox, Edge, and Safari. The API is throttled to the display's actual refresh rate as reported by the OS, so the result reflects your real active refresh rate. Note that mobile browsers may limit frame rate for battery efficiency, so results on phones and tablets may read lower than the display's hardware capability.

60 Hz is the baseline acceptable for most content. 144 Hz is the current standard for competitive gaming, where the smoother motion and lower input lag provide a measurable advantage in fast-paced titles. 240 Hz and above are used by esports professionals where every millisecond of response time matters. For casual gaming and productivity, 60–75 Hz is generally sufficient. For video work, 60 Hz matches most broadcast frame rates well.

This almost always means the monitor is set to 60 Hz in your operating system, not hardware. On Windows: right-click the desktop → Display Settings → Advanced Display Settings → choose 144 Hz from the refresh rate dropdown. On macOS: System Settings → Displays → select the higher rate. Also verify you are using a cable that supports 144 Hz at your resolution (DisplayPort is recommended for 1440p+ at 144 Hz). After changing the OS setting, rerun this test to confirm the change took effect.

Yes, directly. Each frame represents a window of time during which new inputs can be displayed. At 60 Hz, each frame is 16.67ms — your input can be delayed by up to one full frame before appearing on screen. At 144 Hz, that window shrinks to 6.94ms. At 240 Hz, it's 4.17ms. This is why high refresh rate monitors feel more responsive even before accounting for panel response time or GPU render latency. For competitive gaming, the per-frame input lag reduction is as important as the smoother motion.

For 1080p at 144 Hz: any DisplayPort 1.2+ cable or HDMI 2.0+ cable works. For 1440p at 144 Hz: DisplayPort 1.2+ or HDMI 2.0+. For 4K at 144 Hz: DisplayPort 1.4 or HDMI 2.1 required. For 240 Hz at 1440p: DisplayPort 1.4 recommended. For 360 Hz at 1080p: DisplayPort 1.4 or HDMI 2.1. Always use certified cables — cheap adapters or unlicensed cables often cannot sustain the required bandwidth, causing the monitor to drop to a lower refresh rate or produce signal errors.