How to use
- 1
Open the page and wait a few seconds.
- 2
Check that the top motion row looks smoothest.
- 3
If it is lower than expected, fix display settings and measure again.
When to use it
New monitor
Confirm 144 Hz is active.
Cable swap
Check HDMI vs DisplayPort.
Laptops
Battery vs plugged in.
Good to know
- A 144 Hz monitor at 60 Hz: change the refresh rate in Windows display settings.
- Older HDMI may cap the rate; DisplayPort is safer.
- Laptops may raise the rate on AC power.
FAQ
Accurate?
It measures the browser’s actual frame interval.
Like the UFO test?
Same idea.
Phones?
Yes, 120 Hz phones show 120.