CleanLoupePurgeable space on a Mac is storage that is currently in use but that macOS can free by itself the moment another app needs room. Most of it is local Time Machine snapshots, plus some caches and iCloud files that can be re-downloaded. You usually don't need to do anything about it, but if you want the space back right away, you can thin local snapshots with the tmutil command.
Here is what the term means, where to see it, and when it is worth acting on.
What "purgeable" means
macOS uses the APFS file system, which can mark some data as removable on demand. That data still takes up blocks on the disk, so it counts as used, but the system treats it as low priority. When an app asks for space that isn't free, macOS deletes purgeable data to make room, then hands the space over.
Purgeable data typically includes:
- Local Time Machine snapshots. When Time Machine is on, macOS keeps snapshots of the disk on the internal drive so you can restore recent versions even when your backup drive isn't connected.
- Optimized iCloud files. With Optimize Mac Storage turned on for iCloud Drive or Photos, files already stored in iCloud can be removed locally and downloaded again when you open them.
- Some caches that macOS knows how to rebuild.
So purgeable space isn't wasted space. It is space macOS is borrowing for something useful, with a promise to give it back.
Where to see purgeable space
The number shows up in different places, and they don't always agree.
Finder Get Info. Select Macintosh HD in a Finder window (or on the Desktop) and choose File › Get Info. The Available line can read something like "120 GB available (15 GB purgeable)". That means 120 GB can be used, of which 15 GB is currently occupied by purgeable data.
System Settings. In System Settings › General › Storage, the bar shows used space by category. Purgeable data is folded into the categories, and snapshots often end up inside System Data. If System Data looks large, purgeable snapshots may be part of the reason; the System Data guide covers the other parts.
Terminal. df reports only truly free space, which is why it often shows less than Finder:
df -h /
When df and Finder disagree, the difference is mostly purgeable space. Neither is wrong. They answer different questions: "what is empty right now" versus "what can an app have if it asks".
Why the warning can still appear
If macOS can reclaim this space, why do you see "Your disk is almost full"? Because some tools and installers check free space the strict way, before macOS has a chance to purge anything. Some app installers and copy operations check first and refuse. In that case, freeing purgeable space manually can help.
Step 1: List your local snapshots
Open Terminal (Applications › Utilities › Terminal) and run:
tmutil listlocalsnapshots /
You will see lines such as com.apple.TimeMachine.2026-10-01-101500.local. To get just the dates:
tmutil listlocalsnapshotdates /
If nothing is listed, snapshots aren't the source of your purgeable space, and the rest is mostly iCloud and cache data that macOS manages.
macOS keeps local snapshots for about 24 hours and deletes them on its own when space is needed, so the list changes over time. A snapshot you see now may be gone later today.
Step 2: Thin snapshots to reclaim a set amount
The gentlest way to free purgeable space is to ask macOS to thin snapshots until a target amount is reclaimed. The first number is bytes to reclaim, the second is urgency from 1 to 4 (4 is the most urgent):
tmutil thinlocalsnapshots / 20000000000 4
That asks for about 20 GB. macOS removes the oldest snapshots first and stops once it reaches the target or runs out of snapshots. Run df -h / before and after to see the effect.
Step 3: Delete a specific snapshot
To remove one snapshot, use its date from the list in Step 1. This needs your administrator password:
sudo tmutil deletelocalsnapshots 2026-10-01-101500
Replace the date with one from your own list. Deleting a local snapshot doesn't touch the backups on your Time Machine drive; it only removes the copy on the internal disk. You lose the ability to restore that particular point in time while the backup drive is disconnected.
Should you turn off Time Machine to stop snapshots?
You can, but it isn't recommended just to save space. Local snapshots are part of how Time Machine protects you between backups, and macOS already removes them when room is needed. Turning off Time Machine also stops your regular backups. If snapshots keep reappearing, that is the system working as intended.
A better habit: before a large install or file copy that needs a lot of space, thin snapshots once with the command in Step 2, then let macOS manage them again.
Freeing the other kinds of purgeable data
For optimized iCloud files, you don't need to do anything; macOS removes local copies when needed. If you want to force it for a specific file, Control-click it in iCloud Drive and choose Remove Download. The file stays in iCloud and downloads again when you open it. More on that in iCloud Drive taking up space and finding large files.
For caches, macOS purges the ones it owns. App caches you can clear yourself are a separate topic in how to clear cache on Mac.
If the numbers still disagree, why Mac storage numbers don't add up covers the other causes. If purgeable space isn't the issue and you just want to know where your space went, start with what is taking up space on your Mac.
How CleanLoupe handles snapshots
CleanLoupe's Performance module includes a task to thin Time Machine local snapshots. It does the same job as the tmutil commands above, without you having to type a byte count. Backups on your Time Machine drive are not affected.
It doesn't change Time Machine settings, doesn't stop new snapshots from being created, and doesn't touch optimized iCloud files; macOS keeps managing those. CleanLoupe is free (no subscription, trial, ads or account) and runs on macOS 15 Sequoia or later.
The same module also has a "free up purgeable memory" task. Despite the similar name, that is about RAM, not disk space, and its effect is short-lived, so don't expect it to change your storage numbers.
For the rest of your disk, the broader steps are in how to free up space on Mac.
FAQ
How do I get rid of purgeable space on my Mac?
Usually you don't need to, because macOS frees it when an app needs room. If you want it back now, thin local Time Machine snapshots with tmutil thinlocalsnapshots / 20000000000 4 or delete specific snapshots with sudo tmutil deletelocalsnapshots plus a date.
Is purgeable space the same as free space?
Not quite. Free space is empty right now; purgeable space is occupied but can be emptied on demand. Finder's Available figure counts both, while df counts only free space.
Is it safe to delete Time Machine local snapshots?
Yes. They are copies on the internal disk only, and deleting them doesn't affect backups on your Time Machine drive. You only lose those recent restore points while the backup drive is away.
Why does purgeable space keep coming back?
Time Machine creates new local snapshots regularly while it is turned on, and macOS removes old ones over time. A changing purgeable number is normal.
Why is my Mac storage full if I have purgeable space?
Some installers and tools check strictly free space before macOS purges anything. Thinning snapshots before a big install gives them the room they ask for.
Want to thin snapshots without Terminal? Download CleanLoupe and use the Performance module.