Safety Database

Telling unneeded data apart from personal files is a delicate process that leaves no room for guesswork. That's why CleanMyMac relies on a built-in Safety Database — a reference of rules that helps prevent accidental removal of data you need.

Safety Database is an extensive remove-or-keep reference book built into CleanMyMac. Our engineers have been collecting, revising, and updating it since 2008, when the first CleanMyMac version was released. The database aggregates years of experience in cleaning and maintaining Mac computers of millions of users worldwide.

Safety Database includes a large list of cleaning rules, exceptions, and app-specific instructions. CleanMyMac checks this database every time it scans your Mac to make sure that removing the selected data is safe for both the system and your personal files.

Safety Database prohibits removal of essential system files and applications by adding their locations to an ignore list. For example, CleanMyMac won't delete essential files in the /Library or /System/Library folders.

Cache locations usually contain temporary files that apps recreate automatically when needed. In some cases, though, apps store sensitive data, such as licenses or configuration files, in those locations. A good illustration is Spotify, which keeps its local music library among cache files. CleanMyMac respects these unique cases and adds related entries to its Safety Database. It means, in particular, that you can safely remove temporary data from Spotify and continue listening to your favorite playlist offline.

Some apps require quitting all their processes to delete numerous cache files smoothly. Examples include Safari, Google Chrome, Electron-based apps, and apps from JetBrains. Safety Database has a list of such apps and gives CleanMyMac instructions to quit them with your consent and reopen them after cleanup.

When you install an application, its components may be distributed and hidden far beyond the Applications folder. That's why Uninstaller in the Applications module refers to Safety Database when you uninstall an app. The database knows possible app-specific and uncommon locations, so CleanMyMac uninstalls the app along with all of its configuration files, daemons, and other "secret" data.

Our engineers update Safety Database regularly to keep CleanMyMac compatible with all recent macOS updates and newly released apps. The Support Team also reviews user feedback and turns it into new rules when it's reasonable. If you have questions or suggestions about Safety Database, contact Support.