Refresh Rate Test
All three rows only look equally smooth when the browser hits every single frame; stutter shows up first on the fastest row.
The Hz reading is the median frame interval of this tab, so background load or battery-saver mode can pull it below your panel’s rated rate. Everything is measured locally; nothing leaves your device.
How it works
仕組みThis tool measures the refresh rate your browser is actually delivering, right now, on this screen. It times every animation frame the browser paints, takes the median interval, and converts it to hertz, so the reading reflects your real setup: panel, cable, OS settings, battery mode, and browser load all included. The moving blocks underneath are a motion-clarity check in the spirit of the classic UFO test: three rows drift at different speeds, and any dropped frames show up as visible stutter. No spec sheet can answer this for you; only your own machine, in its current state, can.
Browsers only paint as fast as the OS hands them frames. Check that your display settings actually have the higher rate selected: Windows and macOS often default to 60 Hz, especially over the wrong cable or a dock. Battery-saver modes and some browsers on power-saving profiles will also cap the compositor at 60 fps.
Refresh rate is the median frame interval over the last few seconds, a stable estimate of what the display pipeline can sustain. FPS NOW is a short rolling average, so it dips the moment the page or your system gets busy. A healthy setup shows the two numbers sitting within a frame or two of each other.
Stutter means individual frames are being dropped even though the average rate is fine. Background tabs, video calls, or a struggling GPU are the usual culprits. The fastest row shows it first because a single missed frame produces a 16-pixel jump instead of a smooth 16-pixel glide.