Refresh rate and motion test
Observe browser animation timing and compare moving targets for visible blur, trailing and ghosting. Keep the test visible and let its warm-up finish before sampling. Watch the moving target at a repeatable speed and compare any trailing, doubled edges or bright halos when changing monitor settings.
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Test setup
Screen preview
No completed timing sample yet.
Motion targets
Browser animation timing estimate, not certified monitor Hz or panel response time.
- Browser test area (CSS pixels)
- Browser pixel ratio
Sources
- EIZO — monitor test patterns and visual inspectionSources reviewed: 2026-10-31
- MDN — fullscreen browser behaviorSources reviewed: 2026-10-31
- MDN — animation timestamps and foreground behaviorSources reviewed: 2026-10-31
- MDN — CSS pixels and browser scalingSources reviewed: 2026-10-31
How it works
- Start a sample with the page visible and active.
- Read average browser FPS and callback intervals together.
- Compare moving targets at the same speed and picture settings.
Assumptions and limitations
FPS and interval results describe browser animation callbacks, not independently measured panel refresh or response time. Browser load, power management, display changes and background behavior can affect them. Moving patterns support visual comparison; they do not certify hardware Hz, variable refresh or delivered frames.
How to use this tool
Understand the timing result
The browser schedules animation callbacks before repaint. The tool observes the time between those calls and derives average FPS from the mean interval. Longer foreground intervals remain part of the result. This describes the browser's animation cadence during the sample; it does not read the monitor's advertised refresh setting or prove that every callback became a visible frame.
Take a comparable sample
Keep the test visible and let its warm-up finish before sampling. If you hide the tab, change fullscreen state, resize the window or move it to another display, restart the sample. Background pages can stop receiving animation callbacks. For comparisons, keep the browser, display mode and power settings consistent, and note other activity that may affect timing.
Compare motion visually
Watch the moving target at a repeatable speed and compare any trailing, doubled edges or bright halos when changing monitor settings. Motion advances using elapsed time, not a fixed distance per frame. Speeds are in CSS pixels per second, so zoom and scaling affect the physical distance. The observed trail does not yield a calibrated panel response time.
Worked examples
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Interpret a browser timing sample
Keep the tab visible and start a sample after warm-up. A mean interval of about 16.7 ms corresponds to about 60 callbacks per second. If the interval readings vary widely, take another sample under the same conditions.
About 60 browser FPS for this sample
Frequently asked questions
Why can browser FPS differ from the monitor's Hz setting?
The monitor setting and browser callback cadence describe different things. Workload, power settings and browser scheduling can limit or vary the observed rate. Check the actual display setting in the operating system or monitor menu.
Are irregular intervals a count of dropped display frames?
No. They show variation between browser animation calls. A long interval can reflect a scheduling delay, but these timestamps alone do not reveal every frame presented by the display or establish a hardware fault.
Processing and privacy
The calculation or transformation runs in your browser. The tool does not send its input values or generated output to an application server. Loading a page still makes infrastructure requests; optional analytics and Google consent messages have separate controls.
Privacy Policy. Privacy & preferences in the footer controls optional analytics.
Help and feedback
Consult the linked sources for definitions and reference data. Contact Support if you have a question or notice a problem.
Read about calculation methods · Report a problem to emonster
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