How to Free Up Disk Space on Your Mac

When your Mac starts running low on free storage, it can cause real problems, not just an annoying warning message, but slower performance and, if it gets bad enough, an inability to save new files at all. Here’s how to check your storage, understand what’s actually using it, and clear space properly.

For general Mac slowness that isn’t specifically about storage, see our companion guide on troubleshooting a slow Mac. If you’ve already confirmed storage is the issue, read on.

The warning signs

macOS will warn you once your startup disk starts running low on space. It’s worth acting on this sooner rather than later, if you ignore it for too long, you’ll eventually see a much more serious warning that your startup disk is completely full, at which point you won’t be able to save new documents or install updates until you free up space.

Checking how much space you actually have

Open the Apple menu, choose System Settings, click General in the sidebar, then click Storage.

This shows a bar graph of your used and available storage, broken down by category (Applications, Documents, iCloud Drive, Photos, and so on), plus a general “System Data” category that covers Apple and third-party files that don’t fit anywhere more specific. If you see an All Volumes option, it shows the total storage used across every part of the Mac’s internal drive.

As a general target, aim to keep at least 10-15% of your drive free for smooth day-to-day performance.

Letting macOS help manage your storage

From the same Storage settings screen, macOS offers a few built-in options to free up space automatically:

Store in iCloud. Stores files from your Desktop and Documents folders in iCloud Drive, photos and videos in iCloud Photos, and messages and attachments in iCloud, keeping only recently opened files in full on your Mac itself and downloading the rest on demand when you open them.

Optimise Storage. Automatically removes Apple TV movies and shows you’ve already watched, and keeps only recent email attachments on your Mac when space is needed.

Empty Bin automatically. Automatically erases anything that’s been sitting in the Bin for more than 30 days.

macOS can also remove safe temporary files automatically when space is tight, so you do not need to hunt through system caches or logs yourself.

Reviewing specific file categories

Underneath the storage bar graph, you’ll find a breakdown by category that you can click into individually to review and delete files directly:

Applications shows every installed app apart from system apps, with an option to delete apps you no longer use.

Documents covers files in your home folder that do not fit another category. You can sort by name, kind, last accessed or size to find large files and recent downloads.

iCloud Drive shows files stored there, including Desktop and Documents if that setting is enabled. iOS Files contains iPhone and iPad backups and firmware stored on your Mac. Old or duplicate device backups are a common source of wasted space.

TV, Music, Books and Podcasts contains purchases that can be downloaded again later. Mail and Messages include messages and attachments. Music Creation contains GarageBand, Logic and MainStage content.

Photos shows your System Photo Library. Bin shows items you have deleted, although deleted iCloud Drive items are not counted there.

Other ways to free up space manually

Beyond the built-in tools, a few manual checks are worth doing:

Check Downloads for large forgotten files, move older files you rarely need to an external drive, and clear Junk and deleted items in Mail.

A word on “cleaner” apps

If you’re tempted to install a third-party app that promises to automatically clean up and optimise your Mac’s storage, we’d strongly recommend against it. These apps are a common source of real problems, see our companion piece on Mac performance myths for exactly why, and what to use instead.

Still running low?

If you’ve gone through all of the above and you’re still short on space, it might be time to consider an external drive for files you don’t need immediate access to, or a conversation about whether your Mac’s internal storage is simply too small for how you actually use it. Either way, Your Mac Support & Setup team is happy to help you work out the best option.