Is it safe to delete cache files on a Mac?

What is a cache?

A cache is a copy of something an app has already downloaded or calculated, such as web images, thumbnails or compiled code. Keeping it lets the app work faster next time. If the cache is gone, the app simply downloads or calculates it again.

Where caches live on a Mac

• ~/Library/Caches: caches for your user account. This is where most of the space is.
• /Library/Caches: caches shared by all users.
• System caches that macOS manages itself.

The ~ means your home folder. To open it, choose Go › Go to Folder in Finder and type ~/Library/Caches.

How to clear an app's cache safely

1. Quit the app whose cache you want to clear.
2. In Finder, go to ~/Library/Caches and turn on View › Show View Options › Calculate all sizes in list view.
3. Find the folder for that app. It is usually named after the app or its developer, such as com.example.app.
4. Move the folder's contents to the Trash, then empty the Trash.

Delete caches one app at a time rather than emptying the whole folder. That way, if an app misbehaves you know why.

Clearing browser caches

Use the browser's own settings instead of deleting files by hand:

• Safari: in Safari › Settings › Advanced, turn on Show features for web developers, then choose Develop › Empty Caches.
• Chrome: open Settings › Privacy and security › Delete browsing data and choose Cached images and files.

What about system caches?

Leave them to macOS. Apple's own guidance is that starting up in safe mode clears certain system caches, which are recreated as needed, and that this can temporarily make more storage space available on your startup disk.

Things that look like caches but aren't

• ~/Library/Application Support holds app data, settings and sometimes documents.
• ~/Library/Containers and Group Containers hold data for sandboxed apps, such as notes, messages and drafts.
• ~/Library/Preferences holds settings. Deleting files here resets apps.

Is clearing caches worth it?

For a one-off large cache, such as an app you no longer use, yes. For apps you use every day, the cache grows back, so it's a short-term fix. Caches are also why a cleaner's "space freed" figure can drift back down over the following days.

Where TheCleanDisk helps

TheCleanDisk lists caches by app, marks each one Safe or Review, and pre-selects only caches that apps rebuild on their own. Cleaned items go to quarantine first, so you can restore them for 7 days. The space is fully freed when quarantine empties, or sooner if you empty it yourself. It is coming soon to the Mac App Store.