Refresh Rate Test
See how many times per second your screen really refreshes, and whether it matches what your monitor is sold as.
Getting ready…
How It Works
Your browser draws a new frame each time the screen refreshes. The test times every frame; the average gap between frames gives the refresh rate. The number at the top is live.
Pick your monitor’s advertised rate, then run the 5-second test. It counts every frame, and every refresh that passed without one: a dropped frame, shown as a red bar.
Nothing is installed and nothing leaves your device. For the right answer, keep this window on the monitor you are testing and keep the tab in front.
Interpreting Your Result
A 144 Hz or 240 Hz monitor stuck at 60 Hz is the most common problem, and it is almost always a setting or a cable. Set the rate in your display settings (on Windows 11: Settings, System, Display, Advanced display; on a Mac: System Settings, Displays), and use DisplayPort or an HDMI cable that supports the rate.
Some browsers cap the rate on their own. Safari holds pages to 60 Hz unless the “Prefer Page Rendering Updates near 60fps” feature flag is turned off in its settings, and battery saver modes can drop to 30 Hz. If the test is low, plug in your laptop and try another browser before blaming the screen.
Under 1% dropped frames is smooth. Up to 5% is a little stutter; more is visible. Dropped frames usually mean the computer is busy, not a faulty screen: close other tabs and run it again.
Checked the speed? Look for faulty pixels with the dead pixel test. Gaming? See how fast you click with the click speed test.
Frequently Asked Questions
How do I check my monitor’s refresh rate?
Open this page on that monitor. The number at the top is the refresh rate your browser sees, live. Run the test for a full reading, including dropped frames.
Why does my 144 Hz monitor show 60 Hz?
Usually the refresh rate in your display settings is still 60 Hz, or the cable cannot carry more. Set it in your system display settings, and use DisplayPort or a high-speed HDMI cable. A browser in battery saver mode can also cap it.
How do I change my refresh rate?
On Windows 11, open Settings, then System, Display, Advanced display, and pick the highest rate under Choose a refresh rate. On a Mac, open System Settings, then Displays, and set Refresh Rate. If the rate you want is missing, the cable or port cannot carry it: try DisplayPort, or an HDMI cable rated for that rate.
What refresh rate is good for gaming?
60 Hz is fine for everyday use. 120 to 165 Hz is a clear step up in games, with smoother motion and less lag. 240 Hz and above mostly helps fast competitive games, and only if your computer can produce that many frames per second.
Is this test accurate?
It measures what your browser actually draws, averaged over hundreds of frames, so it is accurate to within about 1 Hz. That is the rate you see in practice. A browser can run below the monitor’s maximum, never above it.
Does it work with G-Sync, FreeSync or ProMotion?
Yes. The test shows the rate your browser actually draws at. Variable refresh can run lower for apps in a window, so if the number is below your display’s maximum, put the browser in full screen and test again.