MouseTestLab is a set of free tools for checking a computer mouse in your web browser. Each test gives you a clear result and tells you what to do next, instead of just showing a number.
How we measure
Every test reads the input events your browser reports, with the browser's high-resolution timestamps. We publish how each test works so you can judge the results yourself.
Mouse test. We listen for presses of the five standard mouse buttons and for scroll events. A button counts as working once the browser receives a press from it. Browsers cannot see buttons that your mouse software has remapped to other functions.
Double click test. We record the time of every press and release. A press that arrives less than 15 ms after a release is a switch bounce; two presses of the same button less than 80 ms apart (adjustable) are a fast repeat. During the hold test, a release followed by a press within 300 ms counts as the switch letting go.
CPS test. CPS is clicks divided by the chosen duration. The timer starts with your first click, which counts, and clicks after the end are ignored. We never adjust scores. Results with perfectly even timing (less than 1 ms variation over 20 clicks) or more than 25 CPS on regular tests are marked as auto clickers.
Polling rate test. In Chrome and Edge we read raw mouse events; elsewhere we unpack the events the browser groups per frame. We count reports per 250 ms window while the mouse moves, discard windows with pauses over 20 ms, and report the median.
DPI analyzer. While you hold the button, the pointer is locked and every movement count is added up. Where the browser allows it we request unadjusted movement, so system pointer speed and acceleration are bypassed. DPI is the total distance in counts divided by the inches you moved, averaged over three moves.
Scroll wheel test. In the health check every wheel event during the "down" phase should point down, and vice versa. Events pointing the other way are counted as skips. The first 0.8 seconds after each direction change are ignored.
Mouse accuracy test. A click within the target radius is a hit. We record the reaction time from the moment a target appears and each click's offset from the target centre.
Limits we want you to know about
A browser only sees what the operating system and mouse driver pass on. If a button is remapped, disabled in software or blocked by the browser (Safari does not report side buttons), a test cannot detect it. Our results are a strong signal, not a hardware diagnosis.
Your data
Test results stay in your browser. Personal bests are stored in your browser's local storage and are never sent to us. See the privacy policy for details.