Refresh Rate Test (Hz)
Runs on your device. Nothing is sent.Nothing is uploaded - the frames are counted in your browser.
- Frame time
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- Fastest – slowest frame
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- Jitter
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- Dropped frames
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Motion test
SpeedThe square moves the same distance every second. Smooth, even steps mean every frame arrives on time; stutter or jumps mean dropped frames. Faster speeds make blur and ghosting easier to see.
Seeing 60 Hz on a faster monitor? Check the rate in your system's display settings, plug the cable into the graphics card, and turn off battery saver - browsers drop to 60 Hz to save power.
See your screen's real refresh rate in Hz - 60, 120, 144, 165, 240 or more - with frame times, dropped frames and a motion test, right in the browser.
Find out how many times per second your screen really refreshes. The test counts the frames your browser draws and reports the rate in hertz, snapped to the value on the box (60, 75, 120, 144, 165, 240 Hz and more), along with frame time, jitter and dropped frames. A moving square shows whether motion is smooth. Use it to check a new monitor or laptop, confirm a 144 Hz setting actually took effect, or test a second-hand phone. Nothing is installed and nothing leaves your device.
Frequently asked questions
How does a browser measure the refresh rate?
Browsers draw a new frame once per screen refresh and tell the page when each one starts. The time between two frames is one refresh interval: 16.7 ms at 60 Hz, 6.9 ms at 144 Hz. The test takes the median of the last 300 intervals, so a few slow frames don't skew the result.
Why does it show 60 Hz on my 144 Hz monitor?
Usually the monitor is still set to 60 Hz in the system's display settings, the cable or port can't carry the higher rate (an old HDMI cable, or the motherboard's port instead of the graphics card's), or a laptop on battery has dropped to 60 Hz to save power. Change the setting, then press Measure again.
What do jitter and dropped frames mean?
Jitter is how much the frame times vary; on an idle page it should be well under a millisecond. A dropped frame is one the browser didn't draw in time, so the previous image stays up for two refreshes and motion stutters. A few drops while the page loads are normal; constant drops point to a busy computer or a power-saving mode.
Does it work with variable refresh rates and on phones?
Yes. On G-Sync, FreeSync and phones with adaptive 1-120 Hz screens, the test shows the rate the screen runs at for this page right now, which can be lower than the maximum while little moves. Touch or scroll and many phones jump to their top rate.