Is it safe to delete caches on a Mac? Which ones, and how

Usually safe to delete

• Your user caches in ~/Library/Caches. Quit the app first, then delete its folder. The app rebuilds what it needs.
• Browser caches: clear them from the browser's own settings (for example Safari → Settings → Advanced → Show features for web developers, then Develop → Empty Caches; or Chrome → Delete browsing data → Cached images and files).
• Developer and package caches: brew cleanup, npm cache clean --force, pip cache purge, yarn cache clean, ~/.gradle/caches, and Xcode's DerivedData. They re-download or rebuild on demand.

Be careful with

• /Library/Caches: shared by all users and some system components. Usually safe, but there's little to gain.
• Folders in ~/Library/Application Support: these aren't caches — they hold app data such as libraries, saved games and settings. Only delete a folder there if you've already removed the app.

Don't touch

/System/Library/Caches and anything else under /System belongs to macOS (most of it is protected anyway). DiskGarden won't let you put system locations in the Waste bin.

How much will you get back?

Often a few gigabytes — and some of it comes back as you use your apps. Caches are rarely the main reason a Mac runs out of space; it's usually a few big folders. Scan with DiskGarden to see whether ~/Library/Caches is actually big on your Mac before deleting anything, and find the large files that matter more.