Ghosting Test
Watch moving blocks, bars, text and lines for ghosting trails, motion blur and overdrive halos.
Refresh Rate Test
See the refresh rate your monitor, laptop or phone is running at right now, estimated in Hz from how often your browser draws a frame over 3 seconds. A moving bar shows how smooth that rate looks.
—Hz
Not measured yet
Median frame time: — · Frames sampled: —
Pick the rate your monitor is sold at to check whether it is running at it.
Run the test to get a result you can copy or share.
Showing Motion test
The estimate comes from how often the browser paints, not from the display hardware. Battery saving, browser limits and background load can lower it.
Runs entirely in your browser. Test results, audio and video never leave your device.
How to check your refresh rate
- Close other busy tabs and apps. On a laptop, plug in the charger so power saving does not lower the rate.
- Press Start measuring and keep this tab in front for 3 seconds. Switching away pauses the run.
- Read the result: the estimate in Hz, the closest common rate, the median frame time in milliseconds, how many frames were sampled and the dropped-frame count.
- Pick your monitor’s rated refresh rate from the list under the result. The page then says whether the screen is running at it. If it is lower, work through the fixes below, then press Measure again.
- Press Open motion test, or click the preview. A white bar moves 8 px every frame across the full screen, bouncing between the edges; the preview on the page stays still. Even, smooth motion means every frame arrives; a stutter or brief pause means frames were missed. Space pauses or plays the bar, and Esc exits.
- To judge trails and blur rather than smoothness, use the Ghosting Test.
What is refresh rate?
Refresh rate is how many times per second a screen updates its image, measured in hertz (Hz). A 60 Hz screen updates 60 times a second and a 144 Hz screen 144 times, so motion looks smoother on the faster one, as long as the computer, console or phone supplies a new frame for each refresh.
Your result
The large number is the rate your browser is drawing at, in Hz, estimated from 3 seconds of frames. Under it are the closest common rate, the dropped-frame count, the median frame time and the number of frames sampled. Copy or Share puts the result in one sentence you can paste.
The browser measures how often it draws, not a value read from the display. Battery saving, the browser’s own power settings and the display settings can all hold it below what the screen supports, so a low reading tells you where to look rather than that the monitor is faulty.
Is it at its rated Hz?
Choose the rate your monitor is sold at under Your monitor’s rated refresh rate. After a measurement the page compares the two, allowing 2 percent (at least 1.5 Hz) for timing jitter, so 143.9 Hz counts as 144 Hz but 165 Hz does not count as 170 Hz. It then says the screen is running at its rated rate, below it, or faster than the rate you picked.
The rated rate is on the box, in the manual or on the maker’s product page, often written as 144Hz or 165Hz. In Windows 11, the rate in use is under Settings > System > Display > Advanced display, next to Choose a refresh rate.
Source: Microsoft Support: Change the refresh rate on your monitor in Windows. Checked October 6, 2026.
Fix 60 Hz on a 144 Hz monitor
Stuck at 60 Hz? A reading below the rate your screen is sold with usually means a setting, a cable, a power mode or the browser itself is holding it back. The same checks apply to 120, 165 and 240 Hz screens. Press Measure again after each change.
Windows 11
- Select Start > Settings > System > Display > Advanced display.
- Next to Choose a refresh rate, select the highest rate. A rate marked with an asterisk also changes your resolution.
- If Dynamic refresh rate is on, Windows switches between a lower and a higher rate; it needs a display with variable refresh and at least 120 Hz. For a steady reading, choose a fixed rate in the same list.
- Without the right graphics driver, Windows may offer only a basic 60 Hz mode: install the driver from your PC or graphics card maker.
macOS
- Choose Apple menu > System Settings, then click Displays.
- For an external display, select it at the top first. Then choose a rate from the Refresh Rate pop-up menu.
- On a 14-inch or 16-inch MacBook Pro with Apple silicon, choose ProMotion for the built-in screen’s adaptive rate.
- Safari keeps web pages near 60 frames per second by default, through a feature flag named Prefer Page Rendering Updates near 60fps, so a faster screen can read lower there. Measure in another browser to compare.
Cables, ports and adapters
- Not every cable or input carries the top rate at your screen resolution. Use the input the monitor's manual names for it, often DisplayPort or a recent HDMI version.
- For HDMI, the cable matters as well as the port: HDMI’s own cable guide says an Ultra High Speed HDMI Cable, introduced with HDMI 2.1, carries up to 48 Gbps, enough for 4K at 120 Hz.
- Connect without a dock, hub or adapter to test, then add them back one at a time.
- For Adaptive Sync on a Mac, Apple says not to use an HDMI cable or adapter.
NVIDIA, AMD and Intel graphics settings
- NVIDIA: in NVIDIA Control Panel, choose Change resolution under Display, then pick a rate from the Refresh rate list. With variable refresh (G-SYNC) on, NVIDIA sets the highest rate by itself.
- AMD: in AMD Software: Adrenalin Edition, search for Display and open Display Settings. FreeSync is on by default for supported displays, and Display Specs shows the refresh range the display reports.
- Intel: in the Intel Graphics Command Center, open Displays to change the resolution and refresh rate.
Other things that hold it at 60 Hz
- The monitor's own menu. Some models reach their top rate only after an overclock option is turned on there.
- Mirrored displays. Duplicating one screen onto another runs both at a rate they share.
- Power saving. Laptops can switch to 60 Hz on battery, and battery saver or a browser's energy-saving mode can lower the frame rate. Plug in and turn those off.
Sources: Microsoft Support: Change the refresh rate on your monitor in Windows; Apple Support: Change the refresh rate on your MacBook Pro or Apple display; NVIDIA Control Panel Help: To select a screen refresh rate; AMD: How to enable AMD FreeSync with AMD Software: Adrenalin Edition; Intel: How to fix a flickering screen with Intel Graphics; Apple Support: refresh rate of an external display on Mac; HDMI Licensing Administrator: HDMI cable types. Checked October 6, 2026.
What each rate looks like
Frame time is 1000 ms divided by the refresh rate. The median frame time in your result should be close to the one listed for your screen's rate.
| Refresh rate | Time per frame | Where you usually find it |
|---|---|---|
| 60 Hz | 16.7 ms | Office monitors, and many laptops, TVs and phones |
| 75 Hz | 13.3 ms | Budget and office monitors |
| 90 Hz | 11.1 ms | Some phones and tablets |
| 120 Hz | 8.3 ms | Many recent phones and tablets, some laptops and TVs |
| 144 Hz | 6.9 ms | Gaming monitors and laptops |
| 165 Hz | 6.1 ms | Gaming monitors and laptops |
| 240 Hz | 4.2 ms | Fast gaming monitors |
| 360 Hz | 2.8 ms | Esports monitors |
60 Hz
A new image every 16.7 ms. In the motion test the bar moves 480 px a second, and fast movement, such as a quickly moved mouse pointer, shows visible steps.
120 Hz
Twice as many images as 60 Hz, one every 8.3 ms. Scrolling and pointer movement look clearly smoother, as long as the device draws a new frame for each refresh.
144 Hz
One image every 6.9 ms, the usual rate for gaming monitors. A game needs about 144 frames per second to use every refresh; at a lower frame rate some refreshes repeat the last image.
165 Hz and 170 Hz
About 6 ms per image, a modest step above 144 Hz that many current gaming monitors and laptops offer. Pick the exact rate in the list above, since the two are close.
240 Hz and above
4.2 ms per image at 240 Hz and 2.8 ms at 360 Hz. These rates need a matching frame rate, and a cable and input that carry them at your resolution; the monitor’s manual says which input supports the top rate.
How to check your phone's refresh rate
Open this page on the phone and press Start measuring. Phones with 90 Hz or 120 Hz screens often lower the rate to save power, so a reading of 60 Hz can come from a setting or the browser rather than the screen. Check these, then measure again.
- iPhone and iPad with ProMotion: Low Power Mode, and Limit Frame Rate in the Motion accessibility settings, can each hold the screen at 60 Hz. Safari also keeps web pages near 60 frames per second by default, so a reading near 60 Hz is expected there even when the screen runs faster.
- Android: the refresh rate setting, such as Smooth Display on Pixel phones or Motion smoothness on Samsung phones, can hold the screen at 60 Hz or let it drop when little is moving, and some phones run certain apps at a lower rate. On some phones, Developer options has a Show refresh rate overlay to compare with the reading.
What this test can detect
- The rate your browser is drawing at, in Hz, with the closest common rate, such as 60, 120, 144 or 240 Hz.
- A screen running below the rate it is sold with, once you compare the reading with its specification.
- Dropped frames during the 3-second run, a sign that the browser or device was busy.
- A stutter or brief pause in the moving bar when frames are missed.
- Whether a change of setting, cable or power mode took effect, when you measure again.
How it works
For 3 seconds the test records the timestamp of every frame the browser draws (requestAnimationFrame), skips the first 10 and takes the median gap between them. The estimate is 1000 divided by that median, shown to 0.1 Hz and matched to the nearest of 17 common rates from 30 to 480 Hz. Gaps over 1.5 times the median count as dropped frames. A hidden tab, or 5 seconds without a frame, pauses the run.
The motion test moves a 24 px white bar exactly 8 px per frame, so its speed follows the rate: 480 px/s at 60 Hz, 1152 px/s at 144 Hz.
Limitations
- The reading is how often the browser draws, not a value read from the display. Battery saver, browser power modes, remote desktop sessions and background load can hold it below the screen's real rate.
- It cannot show the highest rate a monitor supports, whether variable refresh (FreeSync or G-Sync) is active, or response time and input lag.
- With screens of different rates connected, the reading can follow another screen instead of the one the window is on. Test with that screen alone if the result looks wrong.
Frequently asked questions
Why does it show 59.9 or 143.8 Hz instead of 60 or 144?
Because the estimate comes from frame timing and is shown to 0.1 Hz. Timing jitter, fractional rates such as 59.94 Hz and browsers that round their timestamps give readings a little off the round number. Compare the closest common rate, shown under the reading, with your screen's rate.
What is the difference between Hz and FPS?
Hz is how often the screen updates; FPS (frames per second) is how many images the computer, game or browser produces. A 60 Hz screen updates 60 times a second however many frames a game renders, so smooth motion needs both a high refresh rate and a frame rate to match.
Can I check 144 Hz with a test video?
No. YouTube and most streaming sites play video at 60 frames per second or less, so a video cannot show whether a screen runs faster than that. A live test that draws a new frame on every refresh, like the one above, can.
What do dropped frames mean?
A dropped frame is a gap between frames much longer than usual, typically because the browser or device was busy. A few are normal; many point to background load. The count covers frames the browser missed, not frames an overclocked monitor skips, which need a camera-based test.
Why does the reading change between runs?
A 3-second run picks up whatever else the device is doing, and adaptive screens, common on phones and some laptops, change rate with content and power state. Run it two or three times with the tab in front, and go by the closest common rate that repeats.