Refresh Rate Test FAQ

A refresh rate test measures how many times per second your screen draws a new image, in hertz (Hz). This one times the frames your browser paints for ten seconds and reports the rate (for example 60Hz, 144Hz or 240Hz), plus frame time, jitter and dropped frames. It is free and runs entirely in your browser.

No. Refresh rate (Hz) is how often the display can show a new image. FPS is how many frames your computer renders. To see 144 distinct frames per second, you need both a 144Hz display and at least 144 FPS. In a browser, animations are synced to the display, so FPS here normally matches Hz.

Not directly. With variable refresh, the display follows the frame rate up to its maximum. A browser animation presents frames as fast as V-Sync allows, so the result normally shows the panel’s maximum rate. A test like this cannot see the lower end of the VRR range.

Yes. It is completely free, needs no download, plugin or sign-up, and works in any modern browser on desktop or mobile.

On a visible tab with hardware acceleration on, the median frame interval is usually within a fraction of a percent of the real rate. You will see values like 143.98Hz or 59.94Hz, which snap to 144 and 60. Background load does not change the median much, but it does show up as dropped frames and lower stability.

Jitter is how much frame times vary, measured as a standard deviation in milliseconds. Low jitter means even pacing. A dropped frame is one that took at least 1.5 times the median frame time, so the display showed the previous image twice. A few drops in ten seconds is normal on a busy machine. Constant drops cause visible stutter.

Many displays run slightly below their nominal rate because of video timing standards. 59.94Hz is a common broadcast-compatible timing. The test shows the raw value for transparency and snaps the headline result to the nearest standard rate when it is within 3%.

The test runs for ten seconds, then locks the result. That is long enough to sample hundreds of frames, even at 60Hz. After it locks, the live readouts and graph keep updating, so you can watch how pacing changes while you open apps or move the window.

Usually the operating system is still set to 60Hz, the cable cannot carry the higher rate, or a power-saving mode is capping it. Set the refresh rate in Windows Advanced display settings or macOS Displays settings, use DisplayPort or a high-speed HDMI cable into the graphics card, and plug in laptops. Then test again.

Go to Settings → System → Display → Advanced display, choose your monitor, and pick the highest rate under “Choose a refresh rate”. If the rate you want is missing, update your graphics driver, use DisplayPort or a high-speed HDMI cable, and check the monitor’s on-screen menu for an overclock or DP version option.

Open System Settings → Displays, select the display, and choose a Refresh Rate. MacBook Pro screens default to ProMotion, which adapts up to 120Hz. External monitors list the rates they support over the current cable or dock.

A reading near 30Hz usually means the browser is capping animation to save power: battery saver, low-power mode, or an unfocused or partly hidden window. Software rendering with hardware acceleration off can also produce low, unstable numbers. Plug in, focus the window and test again.

Yes. Open the page on an iPhone, iPad or Android phone and the test starts on its own. 90Hz and 120Hz phones are detected correctly while they are plugged in or not in low-power mode. Adaptive screens drop their rate to save battery, so that is when a reading comes out lower.

The one the browser window is on. Drag the window fully onto the screen you want to test and press R. If the window spans two monitors with different rates, the browser picks one of them and the result may be unstable.

Results stay in your browser’s local storage on this device: the best rate, how many tests you have run, the last eight readings and your mute and motion-speed settings. Nothing is uploaded, and there is no account. Use Clear in the results bar, or clear site data, to remove them.