Use this free mouse DPI test to estimate your mouse's DPI (CPI) online. Enter a physical movement distance, move your mouse along a ruler, and compare repeated measurements with our mouse DPI checker. No software download required.
Your measurements are not uploaded and are cleared when you refresh.
Use 2–60 cm. In inches, 0.7875–23.6220 is within that range. Default: 10 cm. Measure on your desk, not your screen. After changing units, enter the distance again.
Mark your physical distance. Start, move horizontally once, then finish without moving back.
Either left or right. Keep the mouse facing forward; do not rotate, lift, or backtrack.
Reduce system acceleration (requested). The median uses the latest five valid passes in this mode only. Keep the same mouse DPI setting throughout; reset after changing it.
“Reduce system acceleration” asks the browser for unadjusted movement, but support varies and the request may be ignored. The result is an estimate, not a reading of your mouse's DPI setting. “Use system pointer settings” reports pointer units per inch instead; these depend on system settings and do not represent hardware DPI. See the accuracy limitations before comparing results.
To check mouse DPI online, use a physical ruler and leave enough desk space for one straight pass.
Place a ruler left-to-right beside your mouse and mark 10 cm on your mousepad. Choose one reference point, such as the center of the mouse's front edge. Align that same point with each mark; don't measure from the front at the start and the back at the end.
Choose cm or inches, enter the distance, and select “Reduce system acceleration (when supported)”. Click Start, then wait for “Measuring horizontal movement.” Before moving, check that your reference point is still at the start mark.
Slide left or right without turning or lifting the mouse. Rotation changes the sensor's path relative to your reference point. Stop at the end mark and press Enter, preferably with your other hand, or click once. Don't move back to reach Finish.
Wait for the pointer to unlock, then lift and return the mouse to the start. Complete three to five valid passes with the same DPI preset and measurement mode. Reset the session before changing the preset, browser or system pointer settings.
Measure desk movement, not cursor travel. A 1 mm marking error is 1% of a 10 cm pass, but 5% of a 2 cm pass. Prefer 10 cm or longer if you can keep the whole movement straight.
The analyzer divides the horizontal movement reported by your browser by the physical distance in inches. Screen resolution and display scaling are not used to adjust the result.
Units per inch = absolute net horizontal movement units × 2.54 ÷ distance in cm
For example, 6,299 units over 10 cm gives approximately 1,600 units per inch. That corresponds to CPI only if the browser units equal unscaled sensor counts.
Suppose three valid passes in the same mode give 1,580, 1,600 and 1,620 units per inch. These are illustrative numbers, not measurements from a tested mouse.
A “Valid pass” means enough movement was recorded without too much backtracking or up-and-down drift. It cannot confirm that you moved the distance you entered. If the tool asks you to repeat a pass, follow the stated reason; rejected passes do not enter the median.
If you choose “Use system pointer settings,” keep the browser, system settings and movement speed similar when comparing results. Those numbers describe pointer movement, not hardware DPI. Results from the two modes are kept separate.
DPI is the common marketing term for mouse movement resolution. CPI (counts per inch) describes sensor counts per physical inch more precisely. It does not directly measure accuracy, cursor speed or input latency.
| Nominal setting | Ideal counts over 1 inch |
|---|---|
| 400 DPI | 400 |
| 800 DPI | 800 |
| 1600 DPI | 1,600 |
| 3200 DPI | 3,200 |
These are theoretical relationships, not guaranteed readings from a browser.
Movement resolution: how many counts the mouse reports per physical inch.
How the operating system or a game converts input into cursor or camera movement. This tool is not an aiming or mouse sensitivity test.
How often input updates arrive. Use the mouse polling rate test for a browser-observed Hz estimate.
| Possible cause | What to try |
|---|---|
| Distance measurement error | Use a longer physical distance and clear start/end marks. |
| Diagonal movement or rotation | Keep the mouse facing forward and follow a horizontal ruler. |
| Reversing during the pass | Move in one direction; reposition only after finishing. |
| System acceleration or scaling | Try “Reduce system acceleration”; don't multiply results to match your expected DPI. |
| Browser event processing | Compare another supported desktop browser. |
| Changed DPI preset | Check the current preset in manufacturer software and reset the session. |
| Different movement speeds | Compare three slow passes with three faster passes in separate sessions. |
If the results cluster away from your expected DPI, recheck the physical marks and active preset before changing anything else. Change one condition at a time and reset between sets. A mismatch alone does not establish a sensor fault.
For the configured DPI, check the active profile in your mouse manufacturer's software or its documented DPI-button presets. If several stages are available, confirm which one is selected. Without that software, this ruler-based test provides an estimate, not a readout of the preset.
Windows Settings → Bluetooth & devices → Mouse controls pointer speed. “Enhance pointer precision,” available in additional mouse settings on many Windows 11 versions, can also affect measurements taken with “Use system pointer settings”. Neither setting displays sensor DPI. Turning acceleration off does not prove the browser receives raw sensor counts; keep settings unchanged during each set of passes.
Starting a measurement does not guarantee that system acceleration was removed. Some browsers may ignore that request. This tool cannot read or change hardware DPI, and touchscreens or trackpads cannot substitute for ruler-measured mouse movement.
Accuracy has not yet been checked against known mouse DPI settings across browsers, and compatibility testing is not complete. Treat these results as estimates, even when repeated measurements agree. See how measurements are calculated and checked for more detail.
Reference: MDN Pointer Lock API.
Use a physical ruler to mark a horizontal distance, enter it in the mouse DPI checker, and start measurement. Move once along the ruler, then press Enter or click to finish. Repeat at least three times in the same measurement mode and compare the median. Do not use an on-screen ruler.
No. A website cannot directly read or certify your mouse’s hardware DPI setting. This tool estimates movement units per inch using a measured physical distance and browser-reported movement. Results may vary across browsers and operating systems, even when you choose “Reduce system acceleration”.
Mouse makers commonly use DPI to describe movement resolution. CPI, or counts per inch, is the more precise term for how many counts a sensor reports over one inch of physical movement. Browser movement units are not guaranteed to equal sensor counts.
You can estimate it here without installing software, using a mouse and a physical ruler. To confirm the configured hardware setting, check the manufacturer’s software or the mouse’s documented DPI presets. Windows pointer speed alone does not reveal sensor DPI.
Distance errors, backtracking, diagonal movement, acceleration, browser event processing, and a changed DPI preset can all affect results. Use a longer measured distance, keep the mouse facing forward, and compare three slow passes with three faster passes in separate sessions. A difference does not by itself mean the sensor is faulty.
No. DPI describes movement resolution; polling rate describes how frequently input updates arrive, measured in Hz. Use the mouse polling rate test to estimate browser-observed update frequency.