Screen Refresh Rate (Hz) Detector
Check if your screen is running at 60, 120, 144, or 240Hz.
How to use this page to quickly determine "high refresh/stable/dynamic refresh"
Hz Guide
Use animation loop to estimate rAF interval / FPS.
Take baseline measurements first (animation)
Run for 10 seconds to confirm whether the refresh rate is high and overall stability.
Compare the static mode (to see if the brush is reduced)
Static content is more likely to trigger the system power saving/dynamic refresh strategy and is suitable for judging "whether it will drop to 60/30".
Pressure control (to see if the load is brushed)
When the CPU/GPU is under greater pressure, will frame drops, increased jitter, and refresh rate decrease occur?
FAQ
Frequently asked questions about refresh rate, dynamic refresh and stability judgment.
What is the measured "refresh rate" of this page?
What is measured here is the browser's requestAnimationFrame (rAF) callback rhythm, which is usually strongly related to the screen refresh rate. It reflects the output frequency of the browser's compositing/rendering pipeline and is not equivalent to the monitor panel's "nominal Hz".
How to judge whether it is high refresh rate (90/120/144Hz)?
Run in "Animation" mode for about 10 seconds to see if the "most likely refresh rate" falls stably at 90/120/144 and other gears; also observe whether the "frame interval distribution" is mainly concentrated in one cluster (for example, 120Hz).
Why does it change from 120Hz to 60Hz/30Hz in static mode?
This is a common system power saving/dynamic refresh strategy: reduce the refresh rate when content is stationary to save energy. Different operating systems, browsers, and display (internal screen/external) strategies vary greatly; comparing "animated" and "static" results is the most intuitive method.
What does "dynamic refresh possibility" mean?
When two or more high-proportion frame interval clusters appear within the statistics window (such as 60Hz and 120Hz), it usually indicates that the refresh rate is switching: it may be VRR/adaptive refresh, or it may be load fluctuations that cause the browser to only intermittently reach high refresh rates.
How do you understand "stable/slight fluctuation/unstable"?
It makes an empirical judgment based on the quantile jitter (P90-P10) and standard deviation (std) of the frame interval: the more stable it is, the more concentrated the frame interval is and the subjective smoothness is smoother; the instability may be due to dropped frames, system refresh, excessive background load, or browser frequency limitation.
Why does the result become worse after switching to the background?
The browser actively downclocks or even pauses rAF in the background to save energy and protect resources, so the measured "refresh rate" will drop significantly. This tool will automatically stop when it detects switching to the background. It is recommended to always test in the foreground.
Can this tool accurately differentiate between VRR and performance drops?
It cannot be completely precise. Both will show that the frame interval distribution becomes "more clustered/more scattered". It is recommended that you use a comparison method: switch between "Static" and "Animation", and then use "Stress" mode to verify the load impact; if the stress mode is obviously worse, it is usually more of a performance bottleneck.