How this test works
The test samples animation callbacks after a warm-up and reports a stable estimate when possible.
- Prepare the display using the checklist below.
- Select Start test and allow fullscreen mode if your browser asks.
- Use the arrow keys, on-screen controls, or click the pattern to move through the test.
- Exit the runner and save a local observation if useful.
Before you begin
- Move this window to the display you want to test
- Close heavy tabs and apps
- Keep the page visible during measurement
What to look for
- Estimated browser refresh cadence
- Median frame time
- Warnings for unstable or interrupted samples
Important: This measures browser animation timing, not the panel directly. Variable refresh rate, power saving, system load, and browser throttling can affect results.
Frequently asked questions
Is this my monitor's exact Hz?
It is the cadence observed by the browser. It is usually close to the active output refresh rate when the system is stable.
Why does the value fluctuate?
System load, background activity, variable refresh rate, browser scheduling, and moving the window between screens can disturb samples.
Why do I see 59.94 instead of 60?
Some common display timings operate near 59.94 Hz. Small sampling variation is also normal.