Six ways to free space on a Mac without deleting a single file of yours
Eviction, offloading, compaction and caches. Every technique that returns space while keeping everything you own.
Most cleanup advice starts with what to delete. There is a whole category before that: space held by things that are either duplicated elsewhere, regenerated on demand, or simply not returned yet. None of it involves losing anything.
1. Evict cloud files you already have in the cloud
Any file synced to iCloud Drive, Dropbox, Google Drive or OneDrive exists in two places. Making it online only removes the local copy and keeps the file. Right click a folder in Finder and look for Remove Download or Free Up Space, as covered in what sync folders keep locally.
2. Release purgeable space
tmutil listlocalsnapshots /
sudo tmutil thinlocalsnapshots / 10000000000 4That asks macOS to thin snapshots until roughly 10 GB is available. Snapshots are a safety net rather than files you own, and purgeable space explains what you are giving up, which is the ability to recover a file deleted in the last day or so.
3. Clear caches, which are by definition rebuildable
Package manager caches, browser caches, build output and thumbnail caches are all derived data. On a developer Mac this alone is frequently tens of gigabytes, and the cost is one slow rebuild rather than anything lost. What is in your Library folder covers which caches are which.
4. Compact things that grew and did not shrink
| What | Command or action | Typical gain |
|---|---|---|
| Docker's virtual disk | Prune, then reclaim in settings | Often tens of GB |
| A sparse disk image | hdiutil compact | Whatever was deleted inside |
| A virtual machine disk | The app's reclaim command | Often tens of GB |
| A Photos library | Empty Recently Deleted | Whatever you deleted |
5. Offload media you own to an external drive
Not deletion, relocation. Video projects, photo archives and virtual machines are the obvious candidates, and what moves safely covers which folders tolerate it and which break.
6. Empty the second bins
Photos, Notes, Messages and Mail each hold deleted items for 30 days, and a connected external drive has its own Trash. Emptying those returns space for files you have already decided to delete, which is as close to free as this gets. Every app with a Recently Deleted folder lists them.
What this adds up to
On a typical Mac these six together are worth more than any deletion you were considering, and none of them require a decision about whether you might need something later. Only after they are exhausted is it worth working through the order to free 100 GB.
Common questions
How can I free space on a Mac without deleting files?
Evict cloud files that are already synced, release purgeable snapshot space, clear caches, compact virtual disks and disk images, move media to an external drive, and empty the per app Recently Deleted folders.
What is the safest way to reclaim space on a Mac?
Start with derived data: caches, build output and thumbnails, all of which regenerate. Then evict cloud files that exist in two places. Deletion of files you own should be the last step, not the first.
Does making files online only delete them?
No. The file stays in the cloud service and a placeholder remains in Finder, downloading again when opened. It is the closest thing to free space on a Mac with a synced folder.
How do I reclaim purgeable space immediately?
Use tmutil thinlocalsnapshots with a target amount, which asks macOS to remove local snapshots until that much space is available. What you lose is the ability to recover recently deleted files.