How to free up disk space on Mac, in order.

First, see what's taking up space

Open System Settings › General › Storage and wait for the bar to finish calculating. It splits your disk into categories like Applications, Documents, Photos, and System Data. The biggest category tells you which steps below matter most for your Mac. For more ways to look, including Finder and Terminal, see how to check Mac storage.

Quick wins: how to free up space on Mac in 5 minutes

1. Empty the Trash. Files you've deleted still take space until you do. Choose Finder › Empty Trash, or press Command-Shift-Delete in Finder. Photos and Mail have their own: Recently Deleted in Photos keeps items for up to 30 days unless you delete them there too.
2. Clear out Downloads. Open Downloads in Finder, choose View › as List, and click the Size column. Old installers (.dmg and .pkg files) and zip files you've already opened are safe to move to the Trash.
3. Delete apps you don't use. In Storage settings, click the info button next to Applications to see them sorted by size. Drag the ones you don't need from the Applications folder to the Trash. Big creative apps and games often take 10 GB or more each.
4. Turn on Apple's recommendations. At the top of Storage settings: Store in iCloud keeps your files, photos, and messages in iCloud and only recent ones on your Mac. Optimize Storage removes Apple TV movies and shows you've already watched, and keeps only recent Mail attachments. Empty Trash Automatically erases items that have been in the Trash for more than 30 days.
5. Restart. A restart clears temporary files and swap, and gives macOS a chance to remove old local snapshots. Storage settings also recalculates.

How to clear storage on Mac: the big folders

1. Delete old iPhone and iPad backups. Backups made through Finder live in ~/Library/Application Support/MobileSync/Backup and can be tens of gigabytes each. In Storage settings, click the info button next to iOS Files to see them and delete the ones for devices you no longer have. Where iPhone backups are stored has both ways to delete them.
2. Trim Messages attachments. In Messages, choose Messages › Settings › General and set Keep Messages to 1 Year or 30 Days. Or click the info button next to Messages in Storage settings and delete the largest attachments. See Messages taking up space.
3. Send cloud files back to the cloud. iCloud Drive and Dropbox keep downloaded copies on your Mac. Remove the downloads and the files stay online: see iCloud Drive and Dropbox.
4. Clear caches. Apps keep gigabytes of cached files in ~/Library/Caches, and they rebuild what they need. How to clear cache on Mac covers browsers, apps, and what to leave alone.
5. Find large files. In a Finder window, press Command-F, click This Mac, change Kind to Other › File Size, and search for files greater than 1 GB. Old screen recordings, videos, and disk images are the usual finds.
6. Move big media to an external drive. A Photos library, video projects, or a music collection can live on an external SSD. Copy it, confirm the copy opens, then remove the original.
7. Reclaim System Data. If System Data is the biggest slice, it's usually local Time Machine snapshots, simulator runtimes, or Docker. How to clear System Data walks through each with Apple's own tools.

If you write code

Developer Macs fill up differently. Build folders like node_modules, Xcode's DerivedData, simulator runtimes, package manager caches, Docker images, and local AI models add up fast. To list the node_modules folders in your home folder by size:

find ~ -name node_modules -type d -prune -exec du -sh {} + 2>/dev/null | sort -h | tail -20

Delete the ones in projects you haven't touched in a while; npm install brings them back. For Ollama models, ollama list shows what you have and ollama rm <model> removes one; delete local AI models covers Ollama, LM Studio, and Hugging Face.

Package managers and build tools keep caches of their own, and each has a command to clear it. Clear cache by tool has a page for npm, Docker, Xcode, pip, and six more, and developer files taking up space covers DerivedData, simulators, node_modules, and Docker.raw on one page.

Not sure which folder is the big one? What's taking up space goes folder by folder, including the sleepimage file people often find first.

Your startup disk is almost full: what to do now

When free space gets critically low, macOS shows a warning: “Your disk is almost full,” or on older versions, “Your startup disk is almost full.” Its Manage button opens Storage settings. Take it seriously. With too little room, apps can't save, updates won't install, Messages warns that incoming messages may be lost, and macOS can't grow swap when memory runs short.

1. Make room right away. Empty the Trash and move your biggest downloads to the Trash, then empty it again. Even 10 GB gets you out of the danger zone.
2. Restart. Swap and temporary files are cleared, and macOS gets a chance to release purgeable space it was holding.
3. Work through the checklist. Start with whichever category is biggest in Storage settings.

How to get more storage on Mac

On most Macs, internal storage can't be upgraded after you buy it. You can still get more room:

• iCloud. Store in iCloud keeps the originals online and recent files on your Mac. It needs enough iCloud storage for everything you store.
• An external SSD. Fast enough to keep a Photos library, video projects, or virtual machines on it, and inexpensive per gigabyte.
• Time Machine on an external drive. Backing up regularly lets macOS clear its local snapshots instead of holding them for the next backup.

What not to delete

• Anything under /System. It's on a sealed, read-only volume, and macOS needs all of it.
• Folders in ~/Library/Application Support you don't recognize. That's where apps keep their data, not their caches. Look up a folder before you remove it.
• Commands from forums that start with sudo rm. If a step deletes files as administrator, make sure you know exactly which ones.