MAC OS X - Mos - Mouse Settings - 2026
Mos is a free, open-source macOS utility that makes mouse-wheel scrolling as smooth as a trackpad and lets you remap any mouse button. It runs from the menu bar.
Overview
Mos intercepts mouse-wheel events at the system level and converts discrete scroll steps into continuous, inertia-driven motion. The utility is written in Swift 5, supports macOS 10.13 and later, and is distributed under the CC BY-NC 4.0 license.
The project is authored by Caldis. Source code is available on GitHub.
Features
Smooth Scrolling
Mos uses a physics-based inertia model with three adjustable parameters:
- Step — the minimum scroll distance unit
- Speed — velocity multiplier
- Duration — inertia fade-out time
A simulated trackpad mode is available, making the behavior closely match Apple's native trackpad.
Axis Independence
Vertical and horizontal scrolling can be configured separately:
- Smoothing per axis
- Reverse direction per axis
Scroll Modifier Keys
Modifier keys can be assigned for temporary actions:
- Scroll acceleration
- Direction switching
- Toggle smooth scrolling on/off
Per-App Profiles
Each application can:
- Inherit global settings
- Fully override scroll parameters
- Have its own key and button bindings
For example, smooth scrolling can be enabled in a browser while keeping native behavior in Photoshop.
Button Binding
Any mouse button can be remapped to:
- System actions (Mission Control, Launchpad, Spaces)
- Keyboard shortcuts
- Launch applications
- Run scripts
- Open files
- Custom macros
Event recording is supported: Mos captures keyboard and mouse input, then replays it on button press.
Action Library
Built-in actions:
| Category | Actions |
|---|---|
| Navigation | Mission Control, Launchpad, Dashboard, Spaces switching |
| Screenshots | Screen capture, screen recording, area screenshot |
| Finder | New Finder window, new folder, search |
| Documents | Undo/Redo, Cut/Copy/Paste, Save |
| Media | Volume, Play/Pause, Next track |
| Scrolling | Page up/down, scroll to top/bottom |
Logi / HID++ Support
Mos supports Logitech Bolt, Unifying receivers, and direct Bluetooth connections. Logitech-specific buttons and HID++ events are recognized.
Installation
Manual
- Download the latest release from GitHub Releases
- Extract the archive
- Move Mos.app to /Applications
On first launch, macOS will ask for Accessibility permission. Without it, Mos cannot intercept scroll events. If the app doesn't work after granting permission, see the troubleshooting guide.
Via Homebrew
brew install --cask mos
Update:
brew update brew upgrade --cask mos
Technical Details
- Language: Swift 5
- macOS support: 10.13+
- License: CC BY-NC 4.0
- Mechanism: HID event interception via Accessibility API
- Auto-update: Sparkle
- Permissions: Accessibility, Input Monitoring (for event recording)
System Requirements
- macOS 10.13 High Sierra or later
- 64-bit processor
- ~10 MB disk space
Version
Latest stable release as of 2026 — v4.2.1 (released May 31, 2026).
Contributing
The project welcomes small bug fixes, focused UI/UX improvements, localization, documentation, and tests. Major architectural changes or new features require prior discussion in Discussions.
Acknowledgments
This project uses:
Summary
Mos is a lightweight, free macOS utility that solves a long-standing problem: the jerky, stepped scrolling of regular mice. With its inertia-based algorithm, per-axis and per-app settings, and a powerful button binding system, Mos turns any mouse into a device as comfortable as an Apple trackpad. The project is actively maintained, open-source, and features a rich action library. Logitech HID++ support makes it indispensable for users of that brand.
Links
