Data Transfers · External drive and disk space
Can I download a large file straight to my external drive to save space on my Mac?
Short answer: Yes. Choose Download (or Copy), then set Save to folder or Destination to a folder on your external drive. The file lands there without using space on your Mac.
Yes. In New Transfer, choose Download, then change Save to folder from Downloads to a folder on your external drive with the folder button. The file arrives there without taking room on your Mac.
You can do the same with Copy: pick a folder on the external drive as the destination when bringing files down from a cloud account.
If a download is already running on your Mac and space runs low, it pauses with Needs space, and Move to another drive sends it over to the external drive to finish there.
Related: Download a file from a link · External drives