Monitor Refresh Rate Test

See the refresh rate your screen is really running at.

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Your screen is running at

… Hz

Your monitor's rated refresh rate

Measuring… keep this tab in front and the window on the screen you want to test.

Motion speed

Frame timing details

Measured frames/s

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Frame time

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Dropped frames

1% low

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Worst frame

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Even frame pacing

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Frame skipping check (for overclocked monitors)

One square lights up per frame, in order. Take a photo of it with a slow shutter (1/15 s or longer in your phone's Pro mode) or record slow-motion video. You should see an unbroken run of lit squares. A square that never lights means your monitor is skipping frames.

How this refresh rate test works

Browsers draw animations in step with the display: each time the monitor refreshes, the browser gets one chance to draw a new frame. By timing the gap between frames, this page works out how many times per second your screen refreshes. It then rounds the result to the nearest standard rate, such as 60, 144 or 240 Hz, when the measurement is within a few percent of it.

Pick your monitor's rated refresh rate (it's on the box or in the model's specifications) and the test tells you whether it's really running at that rate. Open Frame timing details to see the time each frame took: a flat line means smooth, even frames, and red dots are dropped frames, moments when a frame took more than 1.5 times longer than usual.

The motion test

The three flying saucers move at the same speed, but the top one is redrawn on every frame, the middle one on every second frame and the bottom one on every fourth, so you can see the difference refresh rate makes on your own screen. On a high-refresh monitor the top lane is noticeably smoother and sharper. If they stutter, the Smooth/Stutter badge turns red and the frame timing details show red dots at the same moment.

Ghosting and overdrive

Switch the saucers' background between Black, Grey and White. A faint trail behind the saucer is ghosting: the pixels change colour too slowly. A bright or dark halo is overshoot (inverse ghosting), caused by an overdrive setting that's too strong. Grey shows both best. If you see either, try a different "overdrive" or "response time" level in your monitor's on-screen menu, then check again.

Frame skipping

Some monitors accept a higher refresh rate than they can really show, especially when overclocked or on a cable that can't carry the full rate. They then drop frames silently: the computer reports, say, 165 Hz, but the screen shows fewer. Open Frame skipping check and photograph the squares with a slow shutter. An even, unbroken run of lit squares means every frame reaches the screen; gaps mean frames are being skipped, so lower the refresh rate a step.

Open Frame timing details for the numbers gamers compare: the 1% low (the frame rate during the slowest 1% of frames), the worst frame, and how evenly frames are paced. If you move this window to another monitor, the test notices and measures that screen instead.

My monitor says 144 Hz but the test shows 60 Hz

This is very common, and it's usually a setting, not a faulty monitor. Work through these checks:

Windows display settings. Go to Settings → System → Display → Advanced display and choose the highest refresh rate in the list. Windows often defaults to 60 Hz.
macOS. Open System Settings → Displays and pick the refresh rate for that display.
Graphics driver. In the NVIDIA Control Panel (Change resolution) or AMD Software (Display), make sure the refresh rate is set to the maximum.
The cable and port. Older HDMI cables and ports can't carry high refresh rates at high resolutions. DisplayPort, or a cable rated for HDMI 2.0 or 2.1, usually fixes it. Plug the cable into the graphics card, not the motherboard.
Laptops on battery. Many laptops drop to 60 Hz on battery to save power. Plug in, or change the power plan.
Browser hardware acceleration. If it's turned off, some browsers cap animation at 60 frames per second. Turn it back on in the browser's settings.
Multiple monitors. With two screens at different rates, some browsers sync to one of them. Move this window to the monitor you want to test and press Restart measurement.

Reading unusual results

A number that isn't standard (for example 59.94 or 143.9) is normal. Displays rarely run at exactly the nominal rate.
Half your expected rate (72 on a 144 Hz monitor) usually means the computer can't keep up, or a power-saving mode is active.
Variable refresh rate (G-Sync, FreeSync, ProMotion) adjusts the rate to the content. On a static page, some screens run at their maximum and others drop lower, so results can vary.
Phones and tablets often lower their refresh rate to save battery, especially in low-power mode.

Frequently asked questions

Is a higher refresh rate better for gaming?

Yes, if your computer can produce enough frames. A higher rate makes motion smoother and reduces the delay before new information appears, which also helps your reaction time.

What is the difference between refresh rate and FPS?

Refresh rate (Hz) is how often the monitor redraws the screen. FPS is how many frames your game or computer produces. If your game runs at 200 FPS on a 60 Hz monitor, you still only see 60 updates per second.

Can this test damage my monitor?

No. It's an ordinary web page with a small animation. It only measures timing.

Why does the result change when I switch tabs?

Browsers slow down background tabs, so the test restarts its measurement when you come back.