How to Free Up Storage on Mac

"Your startup disk is almost full." It's the message every Mac owner gets sooner or later. Here's how to actually fix it without buying a Mac cleaner app (those are mostly scams).

1. Use built-in Recommendations

Apple built four storage tools right into macOS:

• Store in iCloud: moves Desktop, Documents, and Photos to iCloud, keeping smaller previews local
• Optimize Storage: removes watched movies and TV shows from your Mac after you finish them
• Empty Trash Automatically: removes Trash items after 30 days
• Reduce Clutter: opens a detailed view of what's eating space

Apple menu > About This Mac > More Info > Storage Settings. Turn on the ones that make sense for you.

2. Empty the Trash

Sounds obvious, but many people don't realize that Trash counts against storage. Right-click the Trash in the Dock, pick Empty Trash.

Also check the Photos app: it has its own Recently Deleted folder. Open Photos > Recently Deleted > Delete All.

3. Delete old iOS device backups

If you've ever backed up an iPhone or iPad to your Mac, those backups can be 5-20 GB each.

Storage Settings (from step 1) > iOS Files. Review and delete old backups, especially for devices you no longer have.

4. Clean out Downloads

Open Finder, click Downloads in the sidebar. Switch to List view (Command+2). Click the Size column to sort by largest.

Delete files you don't need anymore. Most of what's in Downloads is junk: PDF attachments, installer files, screenshots, things you saved once.

5. Remove apps you don't use

In Storage Settings, click Applications. You'll see apps sorted by size. Move ones you don't use to Trash. Then empty Trash.

Especially worth removing: games you finished, demo apps from when you got the Mac, old versions of apps you upgraded.

6. Clear Mail attachments

If you use the Mail app, attachments accumulate fast. Storage Settings > Mail > review and remove attachments you don't need offline access to.

7. Move large media to an external drive

Video projects, photo libraries, and music collections can be gigabytes. A 1 TB external SSD runs $80-100 and gives you tons of room.

Move:

• Old iMovie or Final Cut projects
• Photo libraries you don't need daily
• Large folder of music or videos
• Old project files from work

8. About System Data ("Other")

If a huge chunk of your storage shows as "System Data" or "Other," some is normal but it can balloon to 30+ GB. To shrink:

• Restart your Mac (clears caches)
• Update to the latest macOS (cleans up old version data)
• Use Storage Settings > Reduce Clutter > sort by Last Accessed to find old files

If System Data stays huge after these steps, the only sure fix is backing up and reinstalling macOS. Save that for true emergencies.

Skip these so-called solutions

Don't install CleanMyMac, MacKeeper, or similar. They duplicate features macOS already has, and several have been flagged as malware. The built-in tools work fine.

Video walkthrough

Video by macmostvideo on YouTube