Containers and Group Containers: what they are and when to clean them

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

Do not delete the Containers or Group Containers folder as a whole. They hold the data of your apps, not temporary copies. Uninstalling an app alone does not make its container disposable. Identify all consumers, inspect retained data, and export and back up anything wanted before considering removal. For an app you still use, removing its container can reset the app or lose your data.

What containers are

Many apps run in a sandbox, which is a set of rules that keeps an app inside its own space. macOS gives each sandboxed app its own folder for its files. That folder is its container.

• ~/Library/Containers holds one folder per app. The folder is named with the app’s identifier, which looks like com.company.appname.
• ~/Library/Group Containers holds folders shared between apps from the same developer, such as an app and its extensions. Their names usually start with a developer code or group..

You can list both folders. These commands only read:

ls ~/Library/Containers
ls ~/Library/Group\ Containers

And see how big they are:

du -sh ~/Library/Containers ~/Library/Group\ Containers

To see which containers are largest:

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

They are data, not caches

This is the key point. A container can hold documents, notes, databases, accounts, settings, downloads and caches, all in one place. Some of it can be rebuilt, and some of it cannot. The folder structure does not tell you which is which.

So the question is not “is the Containers folder safe to clear”. It is “is this app still on my Mac, and do I need what it kept”.

When to clean one

A container is a reasonable target when all of these are true:

• All apps, extensions and services that use it are identified and removed. Skip group containers unless you can verify this for every consumer.
• You have inspected documents, databases, history and other retained data, and confirmed what is unwanted.
• Anything wanted is exported and backed up, and you have verified it can be restored. Time in the Trash is only an extra recovery option.

To check, match the identifier against your apps. An identifier such as com.company.appname normally points to a recognisable app. If you cannot tell, search the web for the exact name before you decide.

What breaks if it goes

• App still installed. It resets. You can lose its documents, accounts, history and settings. Some apps restore from iCloud or their own sign-in. Others cannot.
• Group container. Every app that shares it can be affected, so a loss in one place may show up in another.
• App already removed. Retained documents, databases or history can still be lost. Removal is reasonable only when no consumers remain and wanted data has been preserved.

macOS may also refuse to let some containers be changed without permission. Treat that as a sign to stop and check what the folder is.

The Safe / Risky / Never box

A careful way to do it

1. List the largest containers with the du command above.
2. Identify all apps, extensions and services that use each container. Skip unknown containers and group containers unless every consumer is identified and removed.
3. Inspect documents, databases, history and other retained data. Confirm what is unwanted, export anything wanted and verify a backup you can restore. Keep the container if you cannot complete these checks.
4. Move only reviewed containers to the Trash. Keep them temporarily as an extra recovery option. Before emptying, verify wanted data remains preserved; normal use for a week or two cannot prove archived documents are unnecessary. See why the Trash does not free space.

If an app is still installed and you want space back, use its own settings first. Many apps have a “clear downloads” or “manage storage” option, which is safer than deleting files in its container.

For the same kind of review in a related folder, see Can I delete the Application Support folder?, and for the wider picture, App leftovers on a Mac. The folder-by-folder overview is in what can I safely delete on my Mac.

Common mistakes

• Treating containers like caches. They hold real data, and a container can be the only copy of your notes or documents.
• Deleting by size. A big container may be the app you use most.
• Cleaning a group container for one app. Other apps from the same developer share it.
• Replacing a backup with time in the Trash. Archived documents may not be missed for months. Inspect retained data and verify wanted exports/backups before emptying.

Quick checklist

1. List the containers with the du commands above.
2. Identify every consumer and confirm all are removed; skip unknown containers and group containers with uncertain consumers.
3. Inspect retained data, confirm what is unwanted, export wanted data and verify its backup.
4. Trash only reviewed containers. Before emptying, verify wanted data remains recoverable; waiting alone is not proof.

Where DiskJoy fits

DiskJoy is our product. It scans the folders you choose and reports allocated bytes, a lower bound that excludes shared extents, including large app folders. It is read-only today, and cleanup is not available yet. The scan can show which containers are large before you look for them yourself.