Refresh Rate Test — Measure FPS and Motion Smoothness
This test measures how many animation frames your browser completes each second and how evenly they are spaced, then shows a moving box so you can watch for stutter. It reports the browser's frame rate pipeline, not the panel's hardware refresh rate — an important distinction explained below.
Quick answer: Run the measurement for a few seconds: the counter should settle near your display's refresh rate (60, 120 or 144). Then watch the moving box — stutter that shows as irregular jumps means frames are being missed, usually because another tab, an extension or a background program is stealing time.
Watch the edges of the moving square while the measurement runs: even spacing looks smooth, regular doubling or jumping means uneven frame pacing.
| What it measures | Frames per second delivered to the page by the browser, plus the spacing between frames |
|---|---|
| Typical results | 60, 75, 120, 144 or 240 fps — matching your display's configured refresh rate |
| Not the same as | The panel's hardware refresh rate: browsers cap and pace frames independently of the display |
| Useful for | Spotting stutter, checking that a high-refresh display is configured correctly, and troubleshooting browser performance |
Browser frame rate vs panel refresh rate
The number here is how often the browser renders a frame for the page. The panel may be running at a different rate — browsers usually match the display's refresh rate but cap it in the background, under load, or when energy saving is on. A 144 Hz monitor showing 60 fps here usually means the operating system still has the display set to 60 Hz, which is a common and easily fixed configuration mistake; some browsers also cap frame rate deliberately to save power.
Stutter, pacing and the moving box
Average frame rate hides problems: frames can average 144 fps while arriving in bursts of 141 and 3. The spacing statistics and the moving box expose that. Watch the box's edges — smooth motion means evenly spaced frames, while visible doubling or jumping means irregular pacing. If the pattern is regular, suspect power settings or a background process; if it is random, look at other tabs, extensions and system load.
When to use this test
- You bought a 144 Hz monitor and want to confirm the browser is actually getting high frame rates
- Video and animations stutter in your browser and you want to know whether frames are being dropped
- Comparing two machines or two browsers on the same screen
- Checking whether a battery-saving mode has quietly capped the frame rate