Mac storage almost full? What to do, in order

Updated October 23, 2026

When a Mac runs low on space it slows down, apps refuse to update, and macOS keeps warning you. These steps go from the quickest win to the deepest clean.

1. See what's using the space

Open System Settings › General › Storage. Wait for the bar to finish calculating: it shows how much each category uses, and the recommendations below it are a good place to start.

2. Empty the Trash

Files you delete still take space until the Trash is emptied. Right-click the Trash in the Dock and choose Empty Trash. Some apps, like Photos and Mail, have their own “Recently Deleted” folders too.

3. Find large files

Old videos, disk images and archives are usually the biggest single items. See how to find large files on a Mac.

4. Clean out Downloads

Installers (.dmg, .pkg) and zips you've already opened can go. Sort Downloads by size in Finder to see the biggest first.

5. Remove apps you don't use

Large games, creative suites and old Xcode versions take gigabytes each. Remove their leftovers too: see how to completely uninstall apps.

6. Clear caches and System Data

Caches, logs, developer files and old iPhone backups are often the hidden part of a full disk. See clearing cache safely and clearing System Data.

7. Store things elsewhere

In Storage settings, Store in iCloud and Optimize Storage can keep older files and watched videos in the cloud. An external drive is a good home for photo libraries and video projects.

Keep at least 10–15% of your disk free. macOS needs the room for updates, virtual memory and Time Machine snapshots.

Do it with Disklumo

Disklumo puts the steps above in one window: Clean lists caches, logs, System Data and app leftovers; Apps uninstalls apps with their related files; Analyze maps your whole disk so the largest folders and files stand out. Nothing moves until you confirm, and by default it goes to the Trash.

Questions

How much free space should a Mac have?

Keep at least 10–15% of the disk free. macOS uses free space for updates, virtual memory and Time Machine local snapshots, and gets slow and unreliable when it runs out.

Why is my Mac storage full when I don't have many files?

Usually because of System Data: caches, logs, Time Machine local snapshots, iPhone backups and developer files. Storage settings shows how big it is, but not what's inside.

Do it in one window

Disklumo scans your Mac, shows every item with its size and path, and moves what you choose to the Trash. Clean, uninstall apps, map your disk, watch live status and run maintenance. $17 once, for Apple Silicon Macs on macOS 14 or later.

See Disklumo