Freeing Up Disk Space on Your Mac

Adam Engst, TidBits:

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! Space management on the Mac is now largely indeterminate thanks to APFS, Time Machine snapshots, purgeable space, and more, as Howard Oakley explains. These technologies render the Finder-reported number unreliable at any given point in time. Even after you empty the Trash, it may take macOS several hours or more to update its free space reports. Restarting may or may not help trigger a recalculation.

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. Apple has advice here, and it’s not wrong, but it’s far from comprehensive. macOS also provides tools to help reduce unneeded drive usage at System Settings > General > Storage. Some are worthwhile; others do little or are incomplete. I’ll cover the helpful ones below.

Via Michael Tsai:

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.

I would also be reluctant to delete local copies of iCloud-stored files, either automatically or manually, especially given a bug affecting file versions in the latest release of MacOS Sonoma in certain conditions.

In light of the way APFS and “purgeable” stored files work, Engst is right that it is better to focus on an overall picture of a Mac’s drive rather than specific numbers. I do not know that I will ever get used to the mismatch between what is reported in Finder and the numbers in Disk Utility, but I guess that is just how things will be.

Anyway, I recently wanted to clear up some space on my iMac, and here are two things that worked and one which, for many, will not:

  1. 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.

  2. 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.

  3. The one thing which did not work for me — and this will depend on your specific situation — was sorting applications by size and, in theory, removing the largest unused ones. The problem I have is that virtually all of those really big applications are the ones I need for work. They are typically made by massive and dominant vendors like Adobe, Cisco, Google, and Microsoft, and none of them respect you or your disk space.

    Google Chrome retains old versions in its application file. Microsoft’s OneDrive client for MacOS is 1.2 GB, and all the files for Cisco’s WebEx client occupy around 2 GB, for a file transfer application and a video calling app, respectively. Installing just one of the core Microsoft 365 applications, like Word, will install about 9 GB of shared frameworks.

It feels like users should simultaneously not need to think about disk space and be able to have more direct command over what is stored on it. But there are enough reporting discrepancies, long-expired caches, and uncivil developers making products which are core to many users’ careers to make it seem like we control far less than we would like to believe.

Update: I updated the description of the iCloud bug in Sonoma based on Adam Engst’s feedback to reduce its apparent severity.