Refresh Rate Test

Press Start and keep the tab visible for a few seconds. The test measures how often your browser draws the page and shows the result in Hz, which usually matches your screen refresh rate, such as 60, 120 or 144 Hz.

Refresh Rate Test

Keep this tab visible and still for a few seconds. On a computer with more than one screen, move the browser window to the screen you want to check.

The browser reports how often it draws this page. That usually matches your screen, but battery saver, Low Power Mode, browser frame caps and variable refresh can lower it. Check your display settings for the configured rate.

Estimated refresh rate: Waiting
Exact rate: Waiting
Closest common rate: Waiting
Typical frame time: Waiting
Slow frames in sample: Waiting

Motion comparison

The same block moves at the same speed in each lane, but redraws 30 times a second, 60 times a second or on every frame your screen shows. On a high-refresh screen the bottom lane looks smoothest.

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How to use the Refresh Rate Test

Open this page on the screen you want to check and press Start refresh rate test.
Keep the tab visible and avoid scrolling for a few seconds while frames are measured.
Read the estimated refresh rate and the closest common rate, such as 60, 120 or 144 Hz.
Check the exact rate (two decimals) and the slow-frame count. Stutter or many slow frames can point to frame caps or a busy system.
Press Play motion comparison to see the same block at 30 fps, 60 fps and your screen's full rate.

How the test works

Browsers draw a web page in step with the screen. Each time a new frame is ready, this page records the time. The median gap between frames gives the typical frame time, and 1,000 divided by that time gives the rate in hertz. A 60 Hz screen draws a frame about every 16.7 ms; a 144 Hz screen draws one about every 6.9 ms.

The closest common rate compares the estimate with familiar values like 60, 75, 120, 144, 165 and 240 Hz. If the estimate is not close to any of them, your browser may be limiting frames or the system may be busy.

How to set your refresh rate

Windows 11: Settings › System › Display › Advanced display, then choose a refresh rate. On Windows 10 the same option is under Advanced display settings.
macOS: System Settings › Displays, then pick a Refresh Rate for the display (shown for displays that support more than one).
NVIDIA: NVIDIA Control Panel › Display › Change resolution › Refresh rate.
AMD: AMD Software › Display, and check that FreeSync and the refresh rate match your monitor.
iPhone and iPad: you can’t set the rate, but turning off Low Power Mode lifts the 30 Hz cap.

After changing it, reload this page and run the test again.

When the number looks wrong

Lower than expected: set the rate in your display settings, use a cable and port that support it, and close heavy apps.
Two screens: browsers usually follow the screen the window is on. Move the window and start again.
Laptops and phones: battery saver and Low Power Mode often cap web pages at 30 or 60 Hz.
Background tabs: browsers pause or slow pages you are not looking at, so keep this tab visible.

Frequently asked questions

Why does it show 60 Hz on my 144 Hz monitor?

Check that Windows or macOS display settings use 144 Hz, that the cable and port support it (DisplayPort or a recent HDMI), and that the browser window is on that monitor. Some browsers and battery saver modes also cap pages at 60 Hz.

Why does my iPhone or iPad show 60 Hz or 30 Hz?

Safari can limit web pages to 60 frames per second even on ProMotion screens, and Low Power Mode lowers it further, often to 30. Turn off Low Power Mode and test again; the screen itself may still run faster for system animations.

How accurate is a browser refresh rate test?

It measures how often the browser draws this page, using the median of recent frame intervals. That usually matches the display within a hertz or two, but the browser can draw less often than the screen refreshes, so treat it as an estimate.

What are slow frames?

Slow frames took more than one and a half times the typical frame time. A few are normal when other apps are busy. Many slow frames suggest your system or browser is struggling to keep up.

Why is the exact rate 59.94 or 143.98 Hz instead of a round number?

Many screens and video modes run slightly off the round number, such as 59.94 Hz, and the browser's clock adds a little rounding. Anything within about 1 Hz of the setting is normal.

What do the motion comparison lanes show?

The same block moves at the same speed in each lane, but it is redrawn 30 times a second, 60 times a second, or on every frame of your screen. On a 120 Hz or faster screen the bottom lane looks noticeably smoother. On a 60 Hz screen the bottom two lanes look the same.

Does this work with G-Sync or FreeSync?

Variable refresh changes the rate to match what is drawn, so results can move around. For a stable reading, test in a normal browser window rather than full screen, or check the rate in your display settings.

Last updated: October 12, 2026· Sources: MDN: Window.requestAnimationFrame(), HTML Standard: update the rendering

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