Live frame rate measurement via the browser's rAF clock. Reports current FPS, average, min, max, and 1% low — plus detects whether your display runs at 60, 120, 144, 165 or 240 Hz.
FPS Test is a free, browser-based screen testing tool that lets you measures browser frame rate live using requestAnimationFrame.
This tool uses the browser's requestAnimationFrame callback, which fires once per display refresh. By measuring the time between consecutive callbacks we derive the frames-per-second rate the browser is actually achieving on your device. The result is capped by two things: your monitor's refresh rate (since rAF can't fire faster than the display can update) and any throttling your browser applies (background tabs, power saving, GPU pressure).
Raw FPS numbers fluctuate frame-to-frame, so the meaningful metrics are the averages across a sustained run. "Average" is the smoothed mean of every half-second of rendering. "1% low" is the slowest 1% of frames — this is the number that actually feels like stuttering when gaming or scrolling. A perfect 60 Hz setup shows 60 average / 60 min / 60 max / 60 1%-low. A stuttery setup might show 60 average but 38 for 1%-low, which will feel choppy even though the average is high.
The max FPS over a sustained run is effectively your display refresh rate (as the browser sees it). Common values:
If you expected 144 Hz and see 60 Hz, check Windows Display Settings → Advanced → Refresh rate, and make sure your monitor is plugged into a DisplayPort or HDMI 2.0+ cable with enough bandwidth.
Chrome, Firefox, and Edge all throttle background tabs to save battery and CPU. A tab not in the foreground typically drops to 1 Hz (one frame per second) or suspends rendering entirely. For an accurate reading, keep this tab focused and your browser window in the foreground. Also close other heavy tabs — if another tab is doing GPU work it can steal frames from this one.
If the FPS average looks stable but motion still jumps forward, use the frame skipping test and the frame skipping guide to separate browser frame pacing from physical monitor refresh gaps.
FPS counts how many frames your browser and GPU produce each second. Hz counts how many times per second your display refreshes, no matter what is on screen. A 144 Hz monitor refreshes 144 times a second even if the browser only delivers 60 new frames to it.
In a browser the two are locked together. Rendering runs through requestAnimationFrame, which is effectively always vsync-on, so the browser produces at most one frame per refresh. That is why this test can never settle higher than your active refresh rate — a steady average equal to your Hz is a healthy result, not a hardware limit. (A Max reading a few frames above your Hz is timer jitter, not real extra frames.) Games with vsync disabled can render more FPS than the display shows; browsers offer no such uncapped mode in normal use. To measure the Hz side in depth, run the refresh rate test.
Sometimes the panel really is running at high refresh and it is the browser that delivers 60. Rule out these browser-side causes first — after each change, press Reset, then Start again; the average landing at your panel's rate confirms the fix.
chrome://gpu (or your browser's acceleration toggle), enable it, and restart the browser.If the reading still settles at 60 after these, the cause is usually monitor-side — the OS refresh setting, cable bandwidth, or laptop power mode. Use the refresh rate test and the 144 Hz stuck at 60 Hz guide to work through those step by step.
Smoothness is really about frame time — the gap between screen updates:
The 30-to-60 jump is the biggest perceptual upgrade; 60-to-120 is still obvious in fast motion. For this browser test, a good result is a steady average equal to your refresh rate with the 1% low close behind it — a large gap between the two is the stutter described above. In-game FPS tiers are general guidance only: game performance depends on the title and your GPU, which this browser test does not measure.
FPS Test FAQ
