What to do if Mac says disk is full?

When your Mac is running low on space, old iPhone backups are often a surprising culprit — they can easily run 10–50GB each. To find them, go to System Settings → General → Storage, then scroll down and click iPhone Backups (or iOS Files) in the list. This shows all stored backups with their sizes and dates.

You should delete the old iPhone backup in order to free up space on Mac if Mac says disk is full!

From that same screen, select any backup you no longer need and click Delete Backup to remove it. You can safely delete backups for old devices you no longer own, or older backups if you have a more recent one. Just make sure you have a current backup somewhere (iCloud or another local one) before deleting anything you might need.

If you don't see the option in System Settings, you can also find backups through Finder — connect your iPhone, click it in the sidebar, and under the General tab you'll see a Manage Backups button that lists everything stored locally. From there you can right-click any backup and delete it directly.