How to clear cache on Mac (and which caches to leave alone)

Part of: What can I safely delete on my Mac? Safe, risky and never (Safe to delete)

To clear cache on a Mac, identify its owner and prefer the app’s own cache-control option. Before manual removal, save and sync work, export or back up wanted offline or unsynced data, then quit the app. Only remove verified rebuildable cache contents in a known third-party app’s folder inside ~/Library/Caches. Skip Apple (com.apple.*), unknown and system folders. For browsers, use the browser’s own clear-data option.

Clearing verified rebuildable cache data is usually low risk once wanted offline or unsynced data is protected. The catch is that it is a short-term fix: apps fill their caches again as you use them. Do it when a folder is large and you need the space now.

What a cache is

A cache is a stored copy of something an app can get again, such as a thumbnail or a web page. It makes the app faster. When it is missing, the app builds it again, and the first use is slower.

That is why clearing caches rarely frees space for long. You get the space back until the app needs the same data again.

User caches: safe per app

User caches live in ~/Library/Caches, with one folder per app. Steps:

1. Identify the app whose cache you want to clear. Prefer its own cache-control option. Save and sync work; export or back up wanted offline or unsynced data and verify it is recoverable, then quit the app.

2. List the folders by size to see which ones matter:

   du -sh ~/Library/Caches/* | sort -h

3. Open the folder in Finder:

   open ~/Library/Caches

4. Match the folder to a known third-party app. Skip Apple folders such as com.apple.* and any folder whose owner or contents you cannot verify. Move only rebuildable cache contents to the Trash; leave the folder itself in place.

5. Before emptying the Trash, verify wanted offline or unsynced data remains recoverable and the app works as expected. Waiting or reopening the app alone does not prove all data is disposable. Emptying the Trash frees space permanently. See why the Trash does not free space.

Remove the contents of one app’s folder at a time. Do not select everything in Caches and delete it in one go. A blanket delete can hit apps that are open, and a few apps keep offline downloads there. The Library Caches guide lists the cases that need care.

System caches: leave them alone

There are caches outside your user folder too: /Library/Caches, /System/Library/Caches and the temporary folders under /private/var/folders. macOS and running apps use these. They are managed for you, and the gain from clearing them by hand is small while the risk is real. A cache that a running app expects to find can make the app crash or lose its state.

You can find your own temporary and cache folder under /private/var/folders with:

getconf DARWIN_USER_CACHE_DIR

It only prints a path. Read Can I delete /private/var/folders? before touching it.

Browser caches: clear from the browser

Clear a browser’s cache from inside the browser. Its clear-data dialog lists the cache separately from passwords, cookies and history. Choose only cached images and files. You stay signed in to your sites, and your saved passwords are not touched.

Digging through the browser’s folders by hand is not needed and makes mistakes more likely.

Developer caches

Developer tools such as Xcode keep large caches that rebuild on the next run. Rebuilding can take a long time, so clear them with the tool’s own method when you can. The Xcode cleanup guide covers that case.

The Safe / Risky / Never box

When clearing cache is worth it

• A single app folder is large and you need the space.
• An app shows old or broken content and a fresh start might fix it.

If neither applies, leave the caches. They are doing their job.

Common mistakes

• Using a “clean everything” button without reading the list. Some cleaners delete whole system cache folders. Ask what exactly will be removed.
• Clearing while the app runs. Quit first, or the app can error out.
• Clearing the same cache often. The app slows down each time it refills, so frequent clearing can make the Mac feel slower, not faster.
• Emptying the Trash before checking retained data. Space comes back after emptying, but offline or unsynced work may be lost permanently. Verify wanted data is recoverable first.

Quick checklist

1. Find the largest folders with the du command.
2. Identify a known third-party owner; skip Apple (com.apple.*) and unknown folders, and prefer the app’s cache-control option.
3. Save and sync work; export or back up wanted offline or unsynced data, verify recovery, then quit the app.
4. Trash only verified rebuildable cache contents. Before emptying, confirm wanted data remains recoverable and the app works.
5. Check free space with df -h /, which only reads.

See which caches are large

DiskJoy is our product. It scans your disk and shows reclaimable space by category, including caches. It is read-only today, and cleanup is not available yet. The scan can show which cache folders are worth your attention before you open Finder.