A clone
A copy made on the same disk shares every block with the original. Finder shows both at full size. Trash the copy and nothing comes back.
Trip 2025.fcpbundle12 GBTrip 2025 copyalso 12 GB
Both names point at the same 12 GB of blocks
How to free up space on a Mac without guessing
Start with what will come back, not with what looks biggest. Copies, snapshots and hard links mean the size you see is often not the space you get back. These five steps work on any Mac.
On disk, as Finder shows itWhat you'd get back
Trip 2025 copy.fcpbundleA clone of the library you keep
Report.movEdited today; yesterday's snapshot keeps the old version
Xcode build cacheXcode rebuilds it on the next build
dataset.zipA second name for a file in Projects
Four files on a sample Mac, measured by DiskKind.
Five steps that free space on any Mac
No app needed for any of these. Do them in this order; each one is safe.
Empty the Trash
Space only comes back once you do. Check Downloads and Desktop while you are there.
Clear caches tools make again
Run each tool's own command: npm cache clean --force, brew cleanup and pip cache purge. Every tool
Find large files
In Finder, use List view, turn on Calculate all sizes in View Options, then sort by Size.
Remove old iPhone backups
In Finder, select your device, then Manage Backups.
Restart
macOS shrinks swap files and clears update snapshots it no longer needs.
Three reasons a file can free less than its size
Each one is normal on APFS, the file system every Mac has used since 2017. Finder shows the full size either way.
A snapshot
Time Machine keeps yesterday's version of an edited file. Trash today's version, and the old blocks stay until the snapshot expires.
Report.mov, today9 GBYesterday's snapshotkeeps 5.4 GB
Grey blocks belong to yesterday's version
A hard link
One file can have two names in two folders. Trash one name and the file is still there under the other.
~/Downloads/dataset.zipa name~/Projects/dataset.zipthe same file
Two names, one file of 4.2 GB
Questions about freeing up space
Why didn't deleting files free up space on my Mac?
Usually one of four reasons: the files are still in the Trash, they were clones that share blocks with a file you kept, a local snapshot still holds their old blocks, or they had a second name (a hard link) somewhere else. Empty the Trash first; the other three are what DiskKind shows per file.
Does emptying the Trash free space right away?
Yes, for files nothing else holds. Blocks shared with a clone, or kept by a local snapshot, stay on the disk until the clone is gone or the snapshot expires.
What is purgeable space on a Mac?
Space macOS can free by itself when it needs to, such as iCloud copies it can download again. It counts as available, and macOS decides when to clear it.
See what would really come back on your Mac.
DiskKind measures every file the way APFS counts it, and moves what you choose to the Trash. It never deletes.
