Exclude files from a Time Machine backup on Mac
You can exclude items from a backup to save space on your backup disk, or to exclude items you back up using another method.
On your Mac, choose Apple menu > System Settings > General, then click Time Machine .
Click the Add button , then select one or more items to add to the list of excluded items. You can also drag items to the list.
To remove an item, select it in the list, then click the Remove button .
The backup disk is automatically listed in the list of items that shouldn’t be backed up.
Excluded items still appear in Time Machine local snapshots.
Important: When performing a backup, Time Machine excludes system files and apps installed during macOS installation. If your system is damaged, you must first reinstall macOS on your Mac, then use Migration Assistant to transfer information from a Time Machine backup.