Linux: X11 Mouse Button Numbering
In Linux X11, each mouse button is assigned a number.
Here's the numbering:
- 1 = left button
- 2 = middle button (pressing the scroll wheel)
- 3 = right button
- 4 = turn scroll wheel up
- 5 = turn scroll wheel down
- 6 = push scroll wheel left
- 7 = push scroll wheel right
- 8 = 4th button (aka browser backward button)
- 9 = 5th button (aka browser forward button)
[see Linux: How to Swap Mouse Buttons]
How to find the X11 mouse button number?
type xev
in terminal, then click the button to see its number.

xev
outputTo exit xev
, just close its window.
Mouse Numbering on Windows and Mac
The numbering also depends on Operating System and mouse driver.
For example, on Mac OS X 10.4.x, using a Microsoft 5-buttons mouse, the numbering changes depending on whether you have Microsoft's mouse driver (IntelliPoint) installed.
X11 mouse Numbering Scheme on Mac OS X with Microsoft 5-buttons Mouse without IntelliPoint Software
If you don't have IntelliPoint installed, then Mac OS X doesn't register the mouse wheel tilt left/right, and your Backward (4th) button is the same as right-button, and Forward (5th) button is 4th button.
Here's the numbering reported by emacs's describe-key
.
<mouse-1>
= left button<mouse-2>
= middle button (pressing the scroll wheel)<mouse-3>
= right button<wheel-up>
= roll scroll wheel up<wheel-down>
= roll scroll wheel down- none = push/tilt scroll wheel left (some mouse only)
- none = push/tilt scroll wheel right (some mouse only)
<mouse-3>
= 4th button (aka backward button)<mouse-4>
= 5th button (aka forward button)
See also: Mouse Reviews