Quick answers before you test
Polling rate test vs Hz checker
They describe the same browser-observed measurement here: how many pointer events reach the page each second, plus the interval distribution behind that number.
Why can observed Hz be lower?
Stopping or slowing the mouse, a busy USB hub, power saving and CPU load all thin out the reports. Check Event source too: a browser that only hands the page one event per screen frame reads your refresh rate, not your mouse. Compare repeatable runs before judging hardware.
Read the browser-limit guide →Which result should I record?
Save the observed rate with median interval, P95 interval, gap share and configured mouse rate. Three similar runs are more useful than one peak.
What the result actually measures
Every mouse report that reaches the page is timed with its own timestamp — in Chrome and Edge through raw pointer updates, one per report; elsewhere by unpacking the reports the browser merged into each frame. The rate is the report count over the sample; median and percentile intervals separate a stable stream from a misleading peak.
Measurement boundary: The page sees what the operating system delivers to the browser, not the USB link itself. A browser with neither raw nor merged reports is capped at the display refresh, and the Event source tile says so. The page clock ticks in 0.1 ms, so above about 2000 Hz the rate is counted exactly but single intervals are rounded. A result below the mouse setting does not automatically mean the hardware is faulty.
How to interpret the output
Stable distribution
A narrow interval distribution is often more informative than one maximum reading.
Rate below configured value
Browser delivery, refresh timing, power saving, USB connection or movement speed can reduce the observed rate.
Large spikes
Pauses can come from stopping movement, tab scheduling or main-thread work. Repeat before treating them as device drops.
Troubleshooting unexpected results
Result is capped near display refresh
Look at Event source. One per frame means this browser hands the page a single event per screen refresh, so 60, 144 or 240 Hz is your display. A current Chrome or Edge delivers every report.
Laptop result changes on battery
Power-saving modes can affect CPU scheduling and USB behavior. Compare while connected to power.
Frequently asked questions
Can a browser test 4000 Hz or 8000 Hz?
Yes, in Chrome and Edge, which hand every report to the page with its own timestamp. The count is exact; single intervals are rounded to the browser's 0.1 ms clock, so at 8000 Hz (0.125 ms apart) read the rate rather than the median. The operating system and USB still have to deliver 8000 reports a second, so a port, a hub or CPU load can hold the result below the setting.
Why show median instead of only average?
Median is less distorted by a few long pauses and helps describe the typical delivered interval.
Should I switch to the highest polling rate?
Not automatically. Higher settings can use more CPU/power and the practical benefit depends on the complete system.
