Clearing Space on Your Mac
Glenn Fleishman recently had to wipe one of his teenagers’ Macs after a massive Steam game download led to stalled Time Machine snapshots, resulting in a Mac with just 41K free. They tried numerous approaches to clearing space, but nothing worked—every attempt to delete files was met with errors complaining about the lack of free space.
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Longtime Mac users often get caught up in looking at the amount of free space reported by the Finder. We’ll check the storage numbers shown in a Get Info dialog, delete something, and check again. Don’t waste your time!
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Instead of stressing about exact numbers, I want to offer you a set of steps that will clear space quickly and easily on most Macs.
This is good advice. I would add two things:
Removing local copies of iCloud Drive files is not great because then they are no longer backed up. You can do this in a pinch, but I don’t think it’s a good long-term plan.
If you aren’t the type to keep around huge files/folders that you don’t need, I would start with deleting local Time Machine snapshots. For me, at least, they regularly consume hundreds of GB on my internal SSD to store data that I mostly don’t want (huge files that I’ve downloaded and then discarded or offloaded to a spinning hard drive) and/or that is also on my external Time Machine backups. Carefully pruning files is sort of pointless in a world where Time Machine will just use whatever space you free up to store more snapshots. It certainly does not respect the rule of thumb of keeping 10–20% of the drive free.
However, Engst adds something that I didn’t know but have perhaps seen in action:
Even though the snapshots are on your startup drive, deleting them seems to prevent the Time Machine interface from showing data that has been copied to your external Time Machine drive. If you need to recover something from the time covered by the snapshots, you may be able to do that by manually browsing each Time Machine backup folder in the Finder.
I have lately found the Time Machine restore interface almost useless because it can’t show most of the snapshots. Browsing them directly works great, though.
Previously:
- What Happened to Virtual Memory?
- Free Space Required for Modern macOS Upgrades
- Removing Unwanted APFS Time Machine Backups
- Big Sur Really Needs Real Free Space
- Check Free Space Before Updating to Big Sur
- Quantum Computing and APFS: Free and Used Space
Update (2024-03-21): Nick Heer:
For whatever reason, when iTunes was replaced with Music, MacOS did not remove the now-irrelevant cached Apple Music files from iTunes. Deleting that folder freed up 38 GB of space.
While my photo library is stored on an external disk in Photos, I export selected RAW files to a folder on my local disk and edit those ones in Lightroom. It turns out those files are able to be losslessly compressed through a Lightroom feature called “Update DNG Previews & Metadata”. It is poorly documented and ambiguously named, but running it on my library resulted in a 40% disk space savings — huge, across thousands of photos.
