out of storage on old MacBook Air

Hello antique2020,

Since you don't have enough available storage to update, the steps below can help to free up some storage space:

Optimize storage space

Your Mac can optimize storage by using iCloud to automatically make more storage space available when needed.* And you can use built-in utilities to quickly find and delete files, apps, books, movies, and other items that are taking up space, then delete items you no longer need.

• macOS Ventura or later: Learn how to optimize storage space

• Earlier versions of macOS: Learn how to optimize storage space

Move or delete files

If you have another storage device, such as an external drive connected to your Mac, you can move files to that device. Media files such as photos and videos can use a lot of storage space, so you can take steps such as these:

• Move your Photos library

• Move your iMovie library

You can also delete files that you no longer need. For example:

• Delete music, movies, podcasts, or other media, especially if it's media that you can stream or download again as needed.

• Delete files in your Downloads folder. Open this folder from the Dock, or by choosing Go > Downloads from the menu bar in the Finder.

• If you use the Mail app for your email, choose Mailbox > Erase Junk Mail from the menu bar in Mail. Also choose Mailbox > Erase Deleted Items.

• If you use your Mac to back up your iPhone or iPad, you can delete old backups.

• Uninstall apps that you no longer use.

• If your Mac is set up for multiple users, delete users that no longer need access to your Mac. Or ask them to follow the steps in this article after logging in to their user account. Also check the Users folder on Macintosh HD for any undeleted data belonging to deleted users. 

• Check the Users folder on Macintosh HD for any shared files that you no longer need to share.

If you don't want to delete certain files, you might be able to save space by compressing them. Then expand them when you need to use them again.

Did you empty the Trash? When you move a file to the Trash, its storage space doesn't become available until you empty the Trash.

You can also find those steps in this resource: Free up storage space on your Mac - Apple Support

If you choose to delete any documents or photos, you'll want to first disable those iCloud features on your Mac. That will allow you to delete the items from your Mac without removing them from iCloud or your iPhone: Change iCloud settings for your Apple ID on Mac - Apple Support

Should you have any further questions, don't hesitate to let us know.

Take care.