How the refresh rate test works
Browsers draw a page in step with your display: each time the screen refreshes, they run one animation frame. This test times every frame for about two seconds, takes the median gap to ignore hiccups, and averages the steady frames for a precise figure. It then shows the nearest standard rate (60, 75, 90, 120, 144, 165, 240, 360 Hz and so on) next to the exact measurement. A display sold as 60 Hz often measures 59.94 or 60.00 Hz, and both are normal.
The chart shows the time between recent frames. At 60 Hz the bars sit at about 16.7 ms, at 144 Hz about 6.9 ms. A red bar is a dropped frame: the browser missed a refresh, often because another tab, app or a background task was busy. A few during page load are normal; a steady stream means your computer is struggling or a power setting is throttling it.
Reading the motion test
Follow the objects with your eyes. On a high refresh display the top row looks clearly smoother and less blurred than the 60 fps row, and the 30 fps row judders. If all rows look alike, the browser is not running at the higher rate. The marks under the track make skipped frames visible: they should be evenly spaced, and red gaps show where a frame was missed.
How to turn on a high refresh rate
- Windows 11: Settings, System, Display, Advanced display, then pick the highest value under Choose a refresh rate. On Windows 10 it is under Advanced display settings. Laptops with a Dynamic option switch between 60 Hz and the maximum on their own.
- macOS: System Settings, Displays, then set Refresh rate to ProMotion (MacBook Pro) or the highest rate your external monitor offers.
- iPhone and iPad: ProMotion models run at up to 120 Hz. Low Power Mode and Settings, Accessibility, Motion, Limit Frame Rate both cap the display at 60 Hz. If Safari still shows 60 Hz, turn off the Prefer Page Rendering Updates near 60fps option under Safari's Advanced, Feature Flags settings.
- Android: look for Smooth Display (Pixel) or Motion smoothness (Samsung) in the Display settings. Battery saver usually drops the rate to 60 Hz.
- Chrome and Edge: Energy Saver can limit animations to 30 fps, so switch it off in the Performance settings, and make sure Use graphics acceleration when available is on.
- Firefox: it normally follows your display. If it is stuck at 60 Hz, open about:config and check that layout.frame_rate is -1 (automatic), or set it to your monitor's rate.
- Cables and graphics settings: use DisplayPort or an HDMI 2.0 or 2.1 port and cable. Older HDMI connections often top out at 60 Hz at high resolutions. Also check the refresh rate in the NVIDIA, AMD or Intel graphics control panel.
Why does it show 60 Hz on my 144 Hz monitor?
Almost always the operating system is still set to 60 Hz, the cable or port cannot carry the higher rate, or a power saving mode is active. With several monitors, browsers usually follow the one the window is on, so drag it across and press Measure again. Variable refresh (G-Sync, FreeSync, ProMotion) does not lower the reading: the browser runs at the display's top rate while it animates.
While you are checking your screen, look for stuck or dead pixels with the dead pixel test and check backlight bleed on a black screen. Then see how the faster display affects your reflexes with the reaction time test.
Frequently asked questions
How do I check my monitor's refresh rate?
Open this page and wait about two seconds. The large number is your display's refresh rate as the browser sees it, snapped to the nearest standard value such as 60, 144 or 240 Hz, with the exact measurement shown underneath. To see the setting itself, open the display settings in Windows, macOS or your phone.
Why does the test show 60 Hz on my 144 Hz monitor?
Usually the operating system is still set to 60 Hz, the cable or port can't carry the higher rate (older HDMI often can't), or a power saving mode is limiting frame rates. With several monitors, the browser follows the one the window is on, so move it and press Measure again. Safari may also hold pages at 60 fps unless you change a feature flag.
Why is my result 59.94 Hz instead of 60 Hz?
Many displays and TVs run at 59.94 Hz, a timing inherited from broadcast video, and others at 60.00 Hz. Both count as 60 Hz and the difference is invisible. The test shows the exact figure next to the nearest standard rate so you can see which one your screen uses.
What are dropped frames?
A dropped frame is a refresh the browser missed because it couldn't finish drawing in time. It shows up as a red bar about twice as tall as the others in the chart and as a red gap in the motion test. A few are normal, but many point to a busy computer, a heavy tab or a power setting throttling the graphics.
How accurate is an online refresh rate test?
Very accurate for what the browser actually uses: it times hundreds of animation frames and ignores outliers, so the result is usually within a fraction of a hertz. It can only see the rate the browser runs at, so if a power setting or Safari caps pages at 60 fps, you will see that cap rather than the monitor's maximum.
Can I test my phone's refresh rate?
Yes. Open the page on your phone and it measures the display's rate in the same way. iPhones and iPads with ProMotion reach 120 Hz, but Low Power Mode, the Limit Frame Rate accessibility setting and a Safari feature flag can hold them at 60 Hz. Many Android phones support 90 or 120 Hz when smooth display is switched on.
Is a higher refresh rate better for gaming?
Generally yes. At 144 Hz a new frame arrives every 6.9 ms instead of every 16.7 ms at 60 Hz, so motion looks smoother, moving objects blur less and what you see is more up to date. You only get the full benefit if your graphics card can render that many frames per second in your game.