We measure the gaps between frames your browser actually draws, and estimate your refresh rate from them.
Refresh rate is how many times per second your monitor redraws the screen. At 60Hz that is 60 times a second; at 144Hz, 144 times. Higher numbers mean motion looks smoother and new frames reach your eyes with less delay.
A higher refresh rate shortens the wait before new information appears on screen. One frame is about 16.7ms at 60Hz and about 6.9ms at 144Hz, so in theory you see new information that much sooner. This is part of why reaction time test results can shift by 10-50ms between devices.
| Reading | What it usually means |
|---|---|
| Under ~50Hz | Likely a power-saving mode or browser frame throttling |
| Around 60Hz | Standard for office and entry-level monitors, and most laptop panels |
| Around 75Hz | Common on entry-level gaming monitors |
| Around 120-144Hz | The typical gaming monitor band |
| 165Hz and above | High-refresh gaming monitor |
The browser calls requestAnimationFrame in step with each screen refresh. This test records every gap between those calls for 5 seconds, then computes frames per second from the median gap. The median is used instead of the average so that one or two stray frames during the run cannot skew the result.
If the reading is not what you expected, plug in, close every other tab, and measure again. If it is still low, check your OS display settings.