Mos

Mos is a menu bar utility that smooths mouse wheel scrolling on macOS. A regular wheel moves in coarse steps. Mos takes over the wheel events and turns them into smooth scrolling that feels closer to a trackpad.

You can tune the step size, speed gain and duration, or turn on a mode that simulates a trackpad. Vertical and horizontal scrolling each have their own smoothing and reverse settings, and the mouse and trackpad are handled separately. Hotkeys can speed up scrolling, swap the scroll axis or pause smoothing. Each app can follow the global settings or have its own. Mouse buttons can be bound to actions such as Mission Control, switching Spaces, screenshots, keyboard shortcuts, opening an app or file, or running a script. Logitech devices on Bolt, Unifying or Bluetooth are supported through HID++.

It suits people who use a mouse with a Mac and find the default wheel scrolling jumpy, and anyone who wants extra mouse buttons to do something useful.

Mos is made by Caldis. The code is on GitHub under the Creative Commons BY-NC 4.0 licence, which allows sharing and changes but not commercial use. Mos needs Accessibility permission to read and rewrite scroll events. It supports macOS 10.13 and later and has supported Apple silicon Macs natively since version 3.3.1.