DeviceDIYYour configured monitor refresh rate is best checked in operating-system display settings. A browser refresh-rate test estimates animation callback cadence, which can help identify mismatches but is not a direct panel measurement.
How to test and troubleshoot
Read your configured refresh rate
On Windows 11, open Settings → System → Display → Advanced display and select the correct monitor. Check the available refresh-rate setting.
Use a browser estimate
Open DeviceDIY Refresh Rate Test with the window visible, then start the measurement. Do not switch tabs during the sample.
Compare expected and observed values
If Windows shows 120 or 144 Hz but browser callbacks are near 60, check power-saving mode, secondary displays, remote desktop and browser throttling.
Avoid common measurement mistakes
Close demanding background tasks, keep the browser focused and retest several times.
Interpret variability cautiously
Inconsistent callbacks can arise from software workload or variable refresh features; they do not certify dropped physical frames.
What common test results mean
Browser estimate lower than OS setting
Check power limits and other displays; the browser may run callbacks below the physical refresh rate.
Large frame-time fluctuations
Reduce system workload, keep the tab foregrounded and repeat. Fluctuation alone does not prove monitor damage.
External monitor stuck at 60 Hz
Check cable, dock, port bandwidth and supported display modes in system settings.
Important: A browser test shows the events or signals the browser receives. It does not independently certify hardware condition, software compatibility, data security or the cause of every fault.
Frequently asked questions
Can a web page read my actual panel Hz?
Not reliably across all systems. Browser callback timing is only an estimate.
Does higher Hz always mean fewer dropped frames?
No. Smoothness also depends on frame delivery, synchronisation and software workload.
Technical references
For settings that vary by operating system and browser, refer to official guidance:
Ready to check your device?
Run the matching browser test and see what it actually detects.