Refresh Rate Test
Detect the refresh rate your browser is really running at, then see it in motion.
Detected refresh rate
… Hz
Sampling frames for 5 seconds…
Motion clarity demo
The bars move at your detected frame rate. Higher refresh rates show visibly smoother motion and less ghosting — compare by eye while tracking a bar.
How it works
Browsers repaint in sync with your display, so timing repaints reveals the refresh rate. The test
samples requestAnimationFrame timestamps for five seconds and takes the
median frame interval — a method that shrugs off the occasional stutter or dropped
frame that would skew an average. The result is then snapped to the nearest standard rate (60, 75, 90,
120, 144, 165, 240…) when it's within 3%, since measurement noise of a fraction of a hertz is normal.
Two honest caveats. First, the browser measures the rate the OS is driving the display at — if Windows is set to 60Hz, a 144Hz monitor reads 60Hz here (our refresh rate guide shows where to change it). Second, power saving matters: on battery, many laptops drop the panel rate and browsers throttle animation frames, so plug in before measuring. The motion demo animates bars at your detected rate — the difference between 60Hz and 144Hz is immediately obvious when your eye tracks a moving bar.
What your detected Hz tells you
Refresh rate is how many times per second your display redraws — measured in hertz (Hz). This test samples thousands of animation frames and reports the median interval, accurate to about 1 Hz on an unloaded system. Crucially, it reports the rate your system is actually running, which is often lower than your monitor's maximum spec.
The number one gotcha
If a 144 Hz monitor reads 60 Hz, your operating system is driving it at 60. The panel spec is a ceiling, not the current mode. Fix it in Windows at Settings → System → Display → Advanced display → choose the higher refresh rate; on macOS at System Settings → Displays. Laptops on battery and browser battery-saver modes also throttle to 60 — plug in for a true reading.
Common refresh rates
| Hz | Frame time | Typical use |
|---|---|---|
| 60 | 16.7 ms | Office, general use, most laptops |
| 120 | 8.3 ms | Phones, consoles, entry high-refresh |
| 144 | 6.9 ms | The gaming-monitor standard |
| 240+ | ≤4.2 ms | Competitive esports |
Why small fluctuation is normal
A reading of 143.9–144.1 Hz is just measurement noise. Large drops mean the browser is skipping frames — close heavy tabs, disable battery-saver, and re-run. Higher refresh rates lower the frame time, which is what makes motion look smoother and reduces the delay between your input and the screen updating.
Stuck at 60 even after changing the setting? Check the cable
Refresh rate is limited by cable bandwidth, and this is the most common reason a high-refresh monitor can't be set above 60 or 120 Hz at full resolution. HDMI 1.4 tops out around 1080p 120 Hz / 1440p 75 Hz; HDMI 2.0 reaches 1440p 144 Hz; 4K at 144 Hz needs HDMI 2.1 or DisplayPort. An old cable that came with a different monitor is a classic silent bottleneck — if the OS won't even offer the high rate, swap to a certified DisplayPort or HDMI 2.1 cable before suspecting the monitor. On laptops, also make sure the monitor is plugged into the port wired to the discrete GPU, not the motherboard.
Refresh rate vs frame rate (Hz vs FPS)
The monitor's refresh rate is how often the screen redraws; frame rate is how many frames your game or app produces. A 144 Hz panel showing a game running at 40 FPS still refreshes 144 times a second — it just repeats frames. This test measures the display pipeline only, so it reads full speed even while a game struggles; low FPS in games with a correct reading here means the bottleneck is your GPU or settings, not the monitor. Variable-refresh technologies (G-Sync, FreeSync) sync the panel to the frame rate to remove tearing, and can make this test read slightly below the maximum while active — that is the feature working, not an error.
Troubleshooting
› It reports 60Hz but my monitor is 144Hz
The OS may be running the display at 60Hz — check the refresh rate in display settings, not just the monitor spec. Laptops on battery and some browsers also throttle to save power.
› The number fluctuates slightly
Small variance (e.g. 143.9–144.1) is normal measurement noise. Large drops mean the browser is skipping frames — close heavy tabs and disable battery-saver mode, then re-run.
Frequently asked questions
› How accurate is the detected Hz?
Within about 1Hz on an unloaded system. We sample thousands of animation frames and use the median interval, which is robust to occasional stutters.
› Why does my 144Hz monitor read 60Hz?
Your OS is probably driving it at 60Hz — the monitor spec is the maximum, not the current mode. Set the refresh rate in display settings and re-run.
› Does battery saver affect the result?
Yes. Browsers throttle animation on low-power modes, and some laptops drop the panel to 60Hz on battery. Plug in for a true reading.