Migration Assistant says the new Mac does not have enough space: how to finish the move
Moving from a bigger Mac to a smaller one fails when everything will not fit. Choose what to transfer, move large folders separately, and still keep your account.
Your old Mac has a 1 TB disk with 700 GB used, and the new one is 512 GB. Migration Assistant counts it up and says the new Mac does not have enough space. You do not have to give up on it; you have to choose what comes across.
1. See what is big on the old Mac
# On the OLD Mac
du -sh ~/* 2>/dev/null | sort -h | tail -10
du -sh ~/Library/* 2>/dev/null | sort -h | tail -10Usually a few things are most of it: the Photos library, video projects, iPhone backups, Mail, app data.
2. Untick what you do not need
In Migration Assistant, when it lists what to transfer, expand your user account. You can untick folders such as Movies, Music or Pictures, and choose whether to bring Applications, Other Files and Folders and Settings. The size shown updates as you untick.
3. Move the large things separately
| Item | Better route |
|---|---|
| Photos library | iCloud Photos, or copy to an external SSD |
| Video and old projects | External drive |
| iPhone backups | Make a new one on the new Mac or in iCloud |
| Old downloads and installers | Leave behind |
| Developer caches | Leave behind, they rebuild |
Moving to a new Mac: what not to migrate has the full list of what rebuilds itself.
4. Clean the old Mac first
Deleting old iPhone backups and caches on the old Mac before migrating is often enough on its own. What is safe to delete lists them.
Common questions
What do I do if Migration Assistant says not enough space?
Untick large folders such as Movies or Pictures in Migration Assistant, move those separately to an external drive or iCloud, and clean caches and old backups on the old Mac first.
Can I choose what to transfer with Migration Assistant?
Yes. Expand your user account in the list and untick folders you do not want, and choose whether to bring applications and settings.
Can I migrate from a bigger Mac to a smaller one?
Yes, as long as what you transfer fits. Leave large media and rebuildable caches behind and move them separately if needed.