Mouse Test
Click each button, scroll the wheel and move the pointer to check a mouse or touchpad.
Mouse DPI Test
Move your mouse a measured distance along a ruler, and this page estimates its DPI, the counts per inch your browser receives, from raw movement that leaves out your system's mouse acceleration. Repeat it 3 to 5 times for a steadier estimate.
From 2 to 60 cm. Longer distances give steadier estimates.
Put the mouse at the start of your ruler, then press Start measuring.
Results
- Estimated DPI
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- 0 of 5 runs, 3 more needed for an estimate.
- Spread
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- The lowest and highest run, and the gap between them as a share of the average.
No runs yet.
Optional. The DPI your mouse software or DPI button is set to.
The estimate is only as exact as the distance you move. Line up the same point on the mouse with both marks, move in a straight line with the mouse flat on the pad, and watch the ruler rather than the count.
Runs entirely in your browser. Test results, audio and video never leave your device.
How to check your mouse DPI
- Lay a ruler or tape measure flat beside your mouse, and pick one point on the mouse, such as its left edge, to line up with the marks.
- Type the length you will move into Distance and choose cm or in. It starts at 10 cm; a longer distance gives a steadier estimate.
- Put that point at the start mark and press Start measuring. The pointer disappears while the page measures, and Esc brings it back at any time. After Esc, press Start measuring again for the next run.
- With your point on the start mark, click or press Space, move the mouse along the ruler until your point reaches the end mark, then click or press Space again. Each kept run is added to Runs.
- Lift the mouse back to the start mark and repeat. Estimated DPI appears after 3 runs, and up to 5 runs are kept.
- To compare, type the DPI your mouse software is set to into DPI setting. Remove a run that looks off, or press Reset to start over.
What is mouse DPI?
Mouse DPI, more precisely CPI (counts per inch), is the number of movement counts a mouse's sensor reports for each inch it travels. At 1,600 DPI, moving the mouse 1 inch sends 1,600 counts. A higher DPI moves the pointer further for the same hand movement, and your system's pointer speed and each game's sensitivity scale it again.
Why the estimate can differ from your DPI setting
Small differences between the estimate and the setting are expected. These are the usual causes:
- The distance: stopping 2 mm short over 10 cm makes the estimate 2% low, so line up the same point on the mouse with both marks.
- The sensor: what it reports can differ from the setting, and some mice use separate horizontal and vertical DPI.
- Firmware: smoothing, angle snapping and lift-off distance are handled inside the mouse, before the browser sees any movement.
- The surface: glossy, glass or patterned surfaces can make a sensor skip counts, so measure on a mouse pad.
- The browser: if the gap equals your display scaling and zoom, such as 1.5 times at 150 percent, the browser may be scaling the counts. Enter your DPI setting and the page checks for this.
How to match sensitivity between two mice
Measure both mice here at the setting you use. If both are set to 1,600 DPI and the old one measures 1,590 while the new one measures 1,720, the new mouse moves the pointer about 8% further. To match the old one, set the new one to about 1,480 DPI (1,600 × 1,590 ÷ 1,720).
Keep the same pointer speed in your system for both, and turn off acceleration if you want one hand movement to always cover the same distance. To check the buttons and the scroll wheel, use the Mouse Test; to estimate the polling rate, use the Mouse Polling Rate Test.
What this test can detect
- An estimate of your mouse's DPI (counts per inch) at its current setting: the average of 3 to 5 runs over a distance you measure.
- How consistent your runs are: the spread from the lowest to the highest run, with any run more than 5% from the median marked.
- How far the estimate is above or below the DPI set in your mouse software, as a percentage.
- A gap that equals your display scaling and zoom, which can mean the browser scales the movement it reports.
- Two mice at the same setting that move the pointer differently: measure each and compare their estimates.
How it works
Start measuring locks the pointer with the unadjustedMovement option of the Pointer Lock API, which asks the browser for raw mouse movement without the system's mouse acceleration; without it, the page does not estimate. During a run, the page adds up the movement of every mouse event and takes the straight line from start to end.
Each run's DPI is its counts divided by the distance in inches (centimeters ÷ 2.54). Runs under 20 or over 100,000 DPI are not kept. From 3 runs, Estimated DPI is their average.
Limitations
- It is an estimate that depends on moving exactly the distance you entered. Longer distances and more runs make small placement errors matter less.
- Mouse firmware still affects the estimate: smoothing, angle snapping and lift-off behavior happen inside the mouse, before the browser receives anything.
- It needs raw mouse input, which desktop Chromium browsers, recent Firefox and Safari on a Mac provide. On phones and tablets it may not be available, and the page tells you when it isn't. Some systems turn raw input down as well. Without it, the page does not estimate, because pointer speed and acceleration would change the counts.
- Browsers do not all report movement in the same units. If the gap between the estimate and your DPI setting matches your display scaling and zoom, for example 1.5 times at 150 percent, the browser may be scaling the counts.
- The pointer is hidden while the page measures. Press Esc at any time to get it back. A run in progress is not kept, but earlier runs stay; press Start measuring again to go on.
Frequently asked questions
How do I find out what DPI my mouse is?
Check the mouse's software or specifications first: they list its DPI steps, and some mice show which one is active. To estimate what your browser receives at that step, measure it on this page with a ruler. A DPI button on the mouse changes the step, so note which one is active before you measure.
Is mouse DPI the same as screen DPI?
No. Mouse DPI is how many counts the sensor reports per inch of movement, while screen DPI, or PPI, is how many pixels fit in an inch of a display. To estimate your screen's pixel density, use the Screen DPI Test.
Do pointer speed and mouse acceleration change the result?
Acceleration should not: raw input, which the page requires, leaves it out. Keep pointer speed unchanged between runs. For the test, turn off Windows' Enhance pointer precision; Microsoft says it makes the pointer more accurate when the mouse moves slowly. On a Mac, turn off Pointer acceleration in Mouse settings, under Advanced; the switch first appeared in macOS Sonoma 14.
Is a higher DPI better?
Not by itself. A higher DPI moves the pointer further for the same hand movement, which pointer speed or game sensitivity can also do. What matters is the combination, so choose the setting you find easiest to control and set the sensitivity in each game to match.
What is eDPI?
eDPI, or effective DPI, is your mouse DPI multiplied by a game's sensitivity (800 DPI at 0.5 is 400 eDPI), and it compares sensitivity only between players of the same game, because each game scales sensitivity differently.