How to free up disk space on a Mac, biggest wins first
Free up disk space on a Mac in order of what it gives back: the Storage settings, large files, old downloads, iPhone backups, and what System Data is.
Open System Settings > General > Storage to see what takes the space, then work from the biggest win down: large files you forgot, old installers and archives in Downloads, iPhone backups, and apps you no longer use. Empty the Trash at the end: the space comes back only then. Leave at least 10 to 15 percent of the disk free.
1. See what takes the space
Choose Apple menu > System Settings > General > Storage. Wait a minute for the bar to fill in. Below it, click the ⓘ next to each category:
- Documents lists your largest files, with a Large Files view sorted by size.
- Applications lists apps by size and when you last opened them.
- iOS Files lists iPhone and iPad backups and installers.
- Trash shows what is waiting to be deleted.
The Recommendations at the top are worth reading: Optimize Storage removes watched Apple TV movies and shows, Empty Trash Automatically deletes Trash items after 30 days.
Free toolWhat's in your Downloads folder?See its files by type, size and age in your browser. Nothing is uploaded.2. Find the large files
In Finder, press ⌘F, choose This Mac, and change the first rule to File Size (under Other… if it isn’t listed), is greater than, 1 GB. Save it as a Smart Folder to check again next month (how Smart Folders work).
The usual suspects: video exports and screen recordings, old virtual machines, disk images (.dmg), game files and project archives.
3. Clean Downloads
Downloads is where space disappears without anyone noticing: every installer you ran once is still there.
- Open Downloads (⌥⌘L) in list view.
- Choose View > Use Groups, then group by Kind.
- Select the Disk Image and Installer package groups: once the app is installed, they can go.
- Look at ZIP archive next: if the folder next to it is already unpacked, the ZIP is a duplicate.
Details: how to delete downloads on a Mac.
4. Old iPhone and iPad backups
A single iPhone backup can take tens of gigabytes. In Storage > iOS Files, select old backups and click Delete. You can also open Finder, select your iPhone in the sidebar, and click Manage Backups. Keep the latest backup of each device you still use, or back up to iCloud instead.
5. Apps you don’t use
In Storage > Applications, sort by Last Accessed. Drag the apps you haven’t opened in a year to the Trash. Apps from the App Store can be installed again for free at any time.
6. Messages attachments and mail downloads
In Storage > Messages, review large attachments. In Messages settings, Keep messages can be set to 1 year or 30 days instead of Forever. Mail keeps attachments you opened in ~/Library/Containers/com.apple.mail/Data/Library/Mail Downloads; its content is safe to delete.
7. Empty the Trash
Everything above only moved files to the Trash. Control-click the Trash in the Dock and choose Empty Trash. This is the moment the free space goes up.
About System Data
System Data is what macOS can’t put in another category: caches, logs, Time Machine local snapshots, virtual memory. A lot of it is temporary: restart the Mac and it shrinks. macOS deletes local snapshots on its own when space runs low. Deleting files from ~/Library/Caches by hand is possible, but apps rebuild those caches, and the gain rarely lasts.
Where the manual method stops
The Storage settings tell you how much space each category takes. They don’t sort a folder of 600 mixed files, and they don’t keep Downloads from filling up again next month.
Keep Downloads and the Desktop sorted
DeclutrDeclutr sorts the Desktop, Downloads or any folder into category folders by file type: Documents, Images, Videos, Audio, Archives, Apps, Code & Scripts, 3D Models and more. After one click, the installers and archives sit together in Archives and the videos in Videos, so you can see at a glance what can go. One Undo button puts every file back.
Declutr does not delete anything and does not scan the whole disk: it sorts, and you decide. The sort is free; Pro, a one-time $8.99 purchase in the US, adds rules by age and size, watched folders and a daily scheduled cleanup, so Downloads stays sorted. It needs macOS 13 Ventura or later.
Related: how to delete files on a Mac and where are my downloads on a Mac?
Questions people ask
How do I see what is taking up space on my Mac?
Open System Settings > General > Storage. The bar at the top shows space by category, and the list below it opens each one: Documents lists your largest files, iOS Files lists iPhone and iPad backups, Applications lists apps by size.
What is System Data on a Mac?
Everything macOS can't put in another category: caches, logs, Time Machine local snapshots, virtual memory files and app support data. Much of it is temporary. It shrinks after a restart, and macOS deletes local snapshots on its own when space runs low.
Is it safe to delete the Downloads folder on a Mac?
Deleting what's inside it is safe once you've kept what you need; the folder itself should stay, since browsers save there. Installers (.dmg, .pkg) and archives (.zip) you have already opened are the usual big wins.
How much free space should a Mac have?
Leave at least 10 to 15 percent of the disk free, or around 20 GB on a small drive. macOS needs room for updates, virtual memory and temporary files, and a nearly full disk slows the Mac down.