Free Refresh Rate Test for Estimated Hz, Frame Timing, and Display Stability
Run this refresh rate test to estimate the cadence exposed to the browser using requestAnimationFrame, then review median Hz, frame-time jitter, and long-frame counts.
Run the live browser test
12 practical features in this refresh rate test
requestAnimationFrame sampling
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Warm-up period before measurement
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Median refresh-rate estimate
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Mean refresh-rate estimate
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Median frame interval
Built into this page as an interactive or diagnostic capability, not just a static explanation.
P95 frame interval
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Frame-time jitter
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Long-frame proxy count
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Closest common refresh-rate label
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Fullscreen measurement mode
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Frame-time chart
Built into this page as an interactive or diagnostic capability, not just a static explanation.
Saved test history and export
Built into this page as an interactive or diagnostic capability, not just a static explanation.
How to read the diagnostic signal
| Signal | Useful interpretation | Important limitation |
|---|---|---|
| Stable repeat result | More useful for comparison than a single isolated sample | Still depends on the current browser, OS, and device state |
| Large change after one controlled adjustment | Good clue that the changed variable matters | Correlation is not always proof of root cause |
| Missing or inconsistent browser event | Useful troubleshooting evidence | Does not electrically inspect hardware components |
| Exported session summary | Helps compare before/after changes | Only as good as the test conditions you record |
Worked example: run the same test twice, change one relevant setting, then repeat it. A consistent change across repeated runs is more informative than a single isolated number.
Six short lessons for better testing
Control one variable
Keep device settings, browser zoom, and test mode constant before comparing results.
Repeat the measurement
One run can be noisy. Repeat the same test and look for a stable pattern.
Separate browser from hardware
Browser events are useful diagnostics, but they do not expose every firmware or electrical detail.
Use the right metric
Choose timing, accuracy, count, support, or geometry metrics that match the problem you are investigating.
Record context
Save the device, connection type, relevant settings, and test condition with any result you compare later.
Interpret, do not overclaim
Treat the page as a practical diagnostic aid rather than a laboratory certification instrument.
Complete the diagnostic workflow
Three-question diagnostic quiz
Recent saved milestones on this device
Continue without a dead end
Free Refresh Rate Test for Estimated Hz, Frame Timing, and Display Stability: FAQ
Is this the same as the monitor specification?+
Not always. The tool estimates the cadence the browser receives. Browser throttling, power saving, variable refresh, compositor behavior, and system load can change the result.
How long should I sample?+
A 3–5 second sample is usually enough for a stable estimate. Longer tests can reveal more intermittent frame-time variation.
Why might I see 59.9 instead of 60 Hz?+
Refresh timing is not always an exact integer, and browser timestamps add small measurement variation.
Can this detect variable refresh rate?+
It can show changing frame intervals, but it cannot directly read every VRR mode or panel setting.
Why test in fullscreen?+
Fullscreen reduces some layout distractions and makes it easier to compare measurements, although it does not guarantee a different refresh path.
Use the result responsibly
This tool reports what a browser can observe or calculate in the current environment. Firmware, drivers, operating-system processing, permissions, transport, display timing, audio hardware, device design, and browser implementation can add behavior that this page cannot isolate.
External technical reference: MDN: requestAnimationFrame ↗.