Measure the refresh rate your screen is really running at, and confirm your 144Hz or 240Hz panel didn’t quietly fall back to 60Hz.
Refresh Rate Test — Measure Your Real Hz
Measure your monitor's real refresh rate in the browser. See live Hz, frame timing and stability to confirm a 60, 120, 144 or 240Hz panel runs right.
How to use
- Start measuring. Click Start measuring. The tool counts frames with requestAnimationFrame and shows the detected rate live.
- Let it settle. Wait a few seconds. The average smooths out the first noisy frames and converges on your real refresh rate.
- Read the result. The big number is your measured Hz; Min and Max show how stable it stayed during the run.
Why test this
Setting a refresh rate in your OS and actually getting it are two different things. A high-refresh monitor will quietly fall back to 60Hz over the wrong cable, on the wrong port, or when a display setting never got switched after a driver update. The difference is easy to feel but hard to confirm by eye. This test measures what the browser can actually paint, which is capped by your display, so it tells you the rate your screen is really running at right now. Run it after plugging in a new monitor, swapping a cable, or changing graphics settings to confirm 120, 144, 165, or 240Hz is live and not silently throttled. It is also a quick sanity check when motion looks less smooth than it should: if the number reads far below what you paid for, the problem is in the chain, not your imagination.
What the results mean
The large number is your measured refresh rate in hertz, derived from the average time between frames, and the closest standard line maps it to a common panel rating like 60, 120, or 144Hz. Expect it to land slightly under the rated figure. A 144Hz display commonly reads around 140 to 144 once the compositor and browser overhead are counted, and that small gap is normal. Min and Max show how steady the rate stayed: tightly clustered values mean smooth, consistent output, while a wide spread points to background load or throttling rather than a hardware fault. The moving dot is a smoothness check by eye, so it should glide, not stutter. Keep this the active, focused tab while measuring, because browsers throttle the frame timer in background tabs and that alone can drag the reading down to a misleading 30 or 60Hz.
FAQ
- How does a browser measure refresh rate?
- It times how often the browser can paint a new frame with requestAnimationFrame, which is capped at your display's refresh rate. The frame interval converts directly to Hz.
- Why is my reading a little below my rated Hz?
- Background load, browser throttling, and the OS compositor all add tiny delays. A 144Hz panel often reads around 140 to 144, so a few Hz under the rated number is normal.
- Why does it read much lower in another tab?
- Browsers throttle requestAnimationFrame in background tabs to save power. Keep this tab active and focused for an accurate measurement.
- Does this show if my high refresh rate is actually enabled?
- Yes. If you set 144Hz in your OS but this reads ~60, the display, cable, or graphics setting is not actually running at the higher rate.
- Is this refresh rate test free?
- Yes. It runs entirely in your browser, needs no installation, and stores nothing.
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