How to free up space on your Mac: 10 safe ways

When macOS says your disk is almost full, apps slow down, updates refuse to install and Photos stops syncing. The good news: most Macs have tens of gigabytes that can go without losing anything you care about. Here are ten ways to find them, ordered from quickest to most involved.

1. See what's actually using the space

Open Apple menu › System Settings › General › Storage. The coloured bar splits your disk into Applications, Documents, Photos, macOS, System Data and so on. Give it a minute — the numbers settle as macOS finishes measuring.

The bar is a good start, but it lumps a lot together. "Documents" and "System Data" in particular hide caches, developer files and backups. A tool such as SpaceSweep lists your largest folders, including hidden ones, so you can see exactly which folder is responsible.

2. Empty the Trash

Files you delete stay on disk until you empty the Trash. Right-click the Trash in the Dock and choose Empty Trash. To stop it filling up again, open Finder › Settings › Advanced and turn on Remove items from the Trash after 30 days.

Some apps — Photos, Mail and many photo editors — keep their own trash. In Photos, check Recently Deleted in the sidebar and delete the items there too.

3. Clear out your Downloads folder

Downloads is where installers (.dmg and .pkg files), zip archives and one-off attachments pile up for years. Open it in Finder, switch to list view, and sort by Size to find the big ones. Installers for apps you've already installed are safe to delete.

4. Find and remove large files

In System Settings › General › Storage, click the ⓘ next to Documents and open the Large Files tab to see everything over a few hundred megabytes. Old screen recordings, video exports and virtual machine images are the usual suspects.

You can also search in Finder: press ⌘F, set the first filter to File Size › is greater than › 1 GB, and search "This Mac".

5. Uninstall apps you no longer use

Sort Applications in Storage settings by size. Games, video editors and older versions of Xcode can each take 10 GB or more. Drag unused apps to the Trash, or delete them from the Applications list in Storage settings. Apps from the App Store can be re-downloaded any time.

6. Delete old iPhone and iPad backups

Each local backup of an iPhone or iPad can be as big as the device itself. Connect any device (or just open Finder), select it in the sidebar, click Manage Backups…, and delete backups for devices you no longer own. If you back up to iCloud instead, you don't need the local copies at all.

7. Clear Mail and Messages attachments

Every attachment you open in Apple Mail is saved to a hidden folder, and Messages keeps every photo and video you've ever received. Both can quietly grow to many gigabytes. See how to delete Mail attachments on a Mac for the safe way to clear them.

8. Clear caches and logs

Apps store temporary data in ~/Library/Caches so they start faster. Clearing it frees space and is generally safe, because apps rebuild what they need — but you lose the speed benefit for a while and some apps will sign you out. Read is it safe to delete cache files on a Mac? before you do it by hand.

9. Remove developer files (Xcode, simulators, package caches)

If you write software, this is usually the biggest win. Xcode's DerivedData, old simulators and device support files often add up to 30–100 GB. Package managers keep caches too: ~/.npm, ~/.gradle, ~/.cache and Docker's disk image. Our guide to deleting Xcode DerivedData and other Xcode junk covers what's safe.

10. Let iCloud store files you rarely open

In System Settings › [your name] › iCloud, turn on Optimize Mac Storage for iCloud Drive and, in Photos › Settings › iCloud, Optimize Mac Storage for your library. Full-size originals stay in iCloud and download when you open them. This needs enough iCloud storage to hold them.

What you should never delete

• Anything inside /System, /usr or /bin. macOS protects these anyway, and they make up the "macOS" part of the storage bar.
• ~/Library/Mail itself — that's your mailbox, not a cache.
• ~/Library/Application Support wholesale. Some apps keep their only copy of your data there.
• The Photos library package, unless you've confirmed everything is in iCloud or another backup.

Before a big clean-up, make sure Time Machine (or another backup) has run recently. It's the simplest way to undo a mistake.

Questions

How much free space should a Mac have?

Aim for at least 10–15% of your disk free, and never less than about 20 GB. macOS needs room for virtual memory, software updates and temporary files, and gets noticeably slower when space runs out.

Why is my Mac storage still full after deleting files?

Deleted files stay in the Trash until you empty it, and Time Machine can keep local snapshots of them for up to 24 hours. Empty the Trash and give macOS a little time; snapshots are removed automatically when space is needed.

Does restarting a Mac free up space?

A little. Restarting clears some temporary files and swap, which can free a few gigabytes, but it won't touch caches, downloads or backups.