OnyX
Maintenance Swiss Army knife
freeUtilities
OnyX is a macOS maintenance veteran: cleans system caches, rebuilds Spotlight and LaunchServices indexes, runs maintenance scripts, and exposes hundreds of hidden settings. Each macOS version has its own build — download the exact match for your system.
// Install
Your MacHomebrew in /opt/homebrew
brew install --cask onyx// What it is for
- Collects system maintenance in one window: cache cleaning, database rebuilds, disk verification
- Exposes hidden Finder, Dock, and Safari settings without terminal commands
- A separate build per macOS version — it refuses to run on the wrong one instead of guessing
- Free, and around for two decades
// Common questions
Is cleaning the system with tools like this risky?
OnyX runs macOS's own maintenance routines, but clearing caches always means some data has to be rebuilt — apps start slower right afterwards. Begin with maintenance tasks rather than mass deletion.
Do I need a new version after upgrading macOS?
Yes, always: builds are tied to the OS release. The old version simply refuses to launch on a newer macOS — that is a safeguard, not a bug.