What Is a DPI Switch on a Mouse?

There are places where one size genuinely does fit all, but the computer you work with every day isn't one of them. Getting your computer set just the way you like it takes time, and usually some trial and error. One of the trickiest things to get "just so" is your mouse settings, partly because sometimes it's useful to make it go faster or slower than usual. That's why some mice have a DPI switch, which changes your mouse settings with a single quick click.

The acronym DPI stands for dots per inch, which is a common way computers and their related devices measure resolution. In the case of a mouse, it's a way to express how motion on your desktop translates to your pointer moving on the screen. If your mouse is set for 150 dpi, for example, moving it an inch on your desktop should move it 150 pixels on your screen. If you crank that up to 300 dpi in pixels, or 1,000 dpi, moving your mouse that same inch would move it much, much further across the screen. In real life, mouse dpi doesn't translate directly to screen resolution, because your operating system usually multiplies the dpi to make your mouse work properly on a large, modern high-resolution monitor. The basic idea holds true, though. The higher your resolution, the further your pointer moves on each motion of the mouse.

When you're using your mouse for casual purposes, such as the run of the mill web browsing and word processing that take up much of the day, having it set for a high DPI can be useful. A relatively small motion will send the mouse all the way across even a large monitor, and you won't need a free space on the desk for your mouse. If you're doing precision work, though, like using Photoshop to outline a person or object in a photo, that can be maddening. Turning down the mouse's resolution gives you much finer control, so the movement of your hand on the mouse translates to small and delicate movements onscreen. For example, if you're working on a 300 dpi image, you might want to set your mouse to a lower DPI than you would if you were editing a 2,400 dpi image. You can change your mouse settings manually in your operating system, but that gets tedious if you have to switch back and forth on a regular basis. Using a mouse with a DPI switch speeds the process, and makes it more practical.

Your mouse might have one or more dpi switches, depending on its make and model, but they all do the same job. You'll already have a default setting – your normal, everyday setting for general use – and the DPI switch lets you change to a higher or lower resolution with a single click. With a Microsoft mouse, for example, the first time you click your DPI button you'll be prompted to set an alternative resolution. Once it's set, clicking your DPI button toggles you from your regular resolution to your higher or lower resolution, and then back again on the next click. If your mouse has multiple DPI buttons, you can create a custom setting for each one, so as you change from task to task or monitor to monitor you can adjust your resolution on the fly.

If you have a high-end mouse without a DPI button, it may come with a custom driver or utility program that you can use to adjust the mouse resolution. If not, you'll have to use a similar setting in your OS. Usually it's a simple slider with no numbers, so you'll have to try the slider in different positions to find the one that works best for your purposes.

In Windows, that setting is in the Mouse and Keyboard Center and it's called "Sensitivity." In OS X, you'd go to System Preferences, then click Mouse, and choose the slider called "Tracking." In Ubuntu 18.04 and other versions of Linux using the GNOME desktop environment, choose Show Applications from the bottom of your dock, then Settings, then Mouse & Touchpad. The slider may be labeled as either "Mouse Speed" or "Pointer Speed," depending which version of GNOME is in use on your computer.