Refresh Rate Meter
Measure your screen's actual refresh rate in Hz, detect 60, 90, 120, or 144 Hz panels, and watch frame-time jitter live in your browser.
- Runs locally
- Works offline
- No uploads
Refresh rate
Keep the window in front and scroll or interact while measuring so an adaptive panel runs at its true maximum.
Live reading
About this tool
The Refresh Rate Meter uses requestAnimationFrame to record how long each frame takes to deliver, then computes the average Hz, the nearest standard rate (60, 90, 120, or 144 Hz), and the frame-time jitter.
Everything runs locally in your browser. No data is uploaded or stored.
How it works
- On Start, the meter registers a
requestAnimationFramecallback that fires once per frame. - Each callback records the timestamp delta since the previous frame. The last 120 deltas are kept in a rolling buffer.
- Every second the display updates with the mean Hz (1000 / mean delta), the closest standard rate, the jitter (max delta minus min delta), and the total sample count.
- The bouncing ball animates independently to give you a visual feel of the smoothness while measuring.
Tips for accurate results
- Keep your browser window in the foreground. Background tabs are typically throttled to 1 Hz by the OS.
- On phones with adaptive refresh rates, scroll or interact continuously to prevent the display from dropping to a lower rate.
- Wait at least 2 to 3 seconds for the buffer to fill before reading results.
- Low jitter (under 2 ms) means smooth, tear-free motion. Values above 5 ms suggest scheduler contention or adaptive rate switching.
About the Refresh Rate Meter
Your phone's display spec sheet says 120 Hz, but is the browser actually delivering frames that fast? Adaptive refresh rate technology, battery-saver modes, and browser throttling can all pull the real rate below the advertised maximum. This meter lets you verify what you are actually getting without installing an app.
How refresh rate affects your experience
At 60 Hz each frame is on screen for about 16.7 ms. At 120 Hz that drops to 8.3 ms, which makes scrolling feel noticeably more fluid because the image updates twice as often. At 144 Hz, common on gaming devices, you get 6.9 ms per frame. The difference is easy to see when you scroll a long web page or play a game side by side at two different rates.
What jitter tells you
Two displays can both report 120 Hz but feel very different if one delivers frames unevenly. Jitter is the difference between the longest and shortest frame-delivery interval in the sample window. A steady 120 Hz panel might show 8.3 ms average with under 1 ms of jitter, while a choppy one might show the same average but 4 to 6 ms of jitter, which your eye perceives as stutter.
Adaptive and dynamic refresh rates
Most flagship Android phones since 2020 use adaptive refresh rates that scale from as low as 1 Hz when the screen is static all the way up to 120 or 144 Hz during fast motion. This is great for battery life but can confuse simple benchmark apps. To measure your panel's true maximum, keep scrolling or interacting while the meter runs so the display governor pushes the rate up.
Frequently asked questions
What is screen refresh rate?
Refresh rate is how many times per second your display redraws the image, measured in Hz. A 60 Hz screen redraws 60 times per second; a 120 Hz screen does so 120 times, making scrolling and animations appear twice as smooth.
Why is my result lower than my phone's advertised Hz?
Adaptive refresh rates drop to 60 Hz or lower when the screen is static to save battery. Keep scrolling or interacting while the meter runs to push the display to its maximum. Battery-saver mode and low-power settings can also cap the rate.
What is frame-time jitter?
Jitter is the difference between the longest and shortest frame delivery time in the sample window, in milliseconds. Low jitter (under 2 ms) means steady, stutter-free motion. High jitter causes visible stutter even when the average Hz looks correct.
Can this tool detect 90 Hz and 144 Hz displays?
Yes. The meter classifies the measured Hz to the nearest standard rate among 60, 90, 120, and 144 Hz. If your browser delivers frames at 89.5 Hz the tool will report 90 Hz as the nearest standard. The raw measured value is always shown alongside the classification.