Where apps hide your files

Finding UTM's .utm virtual machine packages

Updated 2026-10-28 · 6 min read

UTM keeps every virtual machine as a .utm package inside its own sandbox container, not in your Documents folder. Here is the path, what is inside a package, and how to copy one safely.

The location

~/Library/Containers/com.utmapp.UTM/Data/Documents/

Each virtual machine UTM creates is one .utm item in that folder, for example Ubuntu.utm. UTM runs in the macOS sandbox, so this "Documents" folder belongs to UTM's container; it is not your own ~/Documents. UTM's release notes say so directly: it is the Documents folder in UTM's sandbox, "not the user's documents directory".

The Library folder is hidden. In Finder choose Go > Go to Folder (⇧⌘G), paste the path and press Return. From Terminal:

open ~/Library/Containers/com.utmapp.UTM/Data/Documents

To list the machines and their sizes without opening anything:

ls -lh ~/Library/Containers/com.utmapp.UTM/Data/Documents
du -sh ~/Library/Containers/com.utmapp.UTM/Data/Documents/*.utm

The quickest route of all is in the app: right-click a machine in UTM's list and choose Show in Finder. That also works for machines kept outside the container (see below).

App Store build or direct download

UTM is on the Mac App Store and offered free from its GitHub releases. UTM's installation page says the App Store version is identical to the GitHub version, with no features left out; its only advantage is automatic updates. In UTM's source both are built with the bundle identifier com.utmapp.UTM and the App Sandbox switched on, which is why they use the same container. If the path is empty on your Mac, check what is there (names only):

ls ~/Library/Containers | grep -i utm

A machine made with a very old release may still sit in ~/Documents. UTM 2.0.17 turned the sandbox back on, and its notes told people to move their .utm files from ~/Documents into the container's Documents folder by hand.

UTM is not installed on the Mac used for this guide, so everything here comes from UTM's documentation, release notes and source code.

A .utm file is a folder

A .utm item looks like one file in Finder, but it is a package. Right-click it and choose Show Package Contents to look inside. UTM's source names the parts:

• config.plist, the machine's settings.
• A Data folder holding the disk images, for example a .qcow2 file for a QEMU machine, and efi_vars.fd for a machine with UEFI firmware.

UTM's drive documentation says non-removable drives are stored inside the .utm package, so the whole machine, disks included, travels as one item. Removable drives are different: UTM keeps only a bookmark to the image, so an installer ISO stays wherever you saved it.

Since UTM 4.0.2, host-specific settings such as window options and bookmarks to removable drives are kept in a registry outside the package (in UTM's own preferences), so the package copies cleanly between Macs.

How big it gets

When the package sits on an APFS volume, UTM creates new raw disk images as sparse files, so a "64 GB" drive does not use 64 GB on day one. It grows as the guest writes data. Compare real and apparent size:

du -sh ~/Library/Containers/com.utmapp.UTM/Data/Documents/*.utm
ls -lhR ~/Library/Containers/com.utmapp.UTM/Data/Documents/Ubuntu.utm/Data

Replace Ubuntu.utm with your machine. du shows space actually used; ls shows the size the guest sees.

Space freed inside the guest is not handed back on its own. For QEMU machines, UTM's drive settings offer Reclaim Space and Compress, which rewrite the image as QCOW2 and release unused space. UTM's documentation calls these experimental and says to back up the machine first, and they cannot run while the drive has snapshots or a suspended state.

Snapshots count too. UTM's documentation says a snapshot holds the contents of the machine's writable drives, plus the running state when taken from a running QEMU machine. Delete old ones from the machine's Snapshots tab, which removes the snapshot and all its data.

Moving, copying and backing up

Shut the guest down first. A package copied while it runs can be inconsistent.

• Move it to another drive: right-click the machine and choose Move..., described in the app as moving the VM "from internal storage to elsewhere". It then stays in UTM's list, stored in the new place.
• Copy it: right-click and choose Share..., which shares a copy with all its data, or copy the .utm in Finder.
• Open one from elsewhere: File > Open... (⌘O) or a double-click adds a .utm from another folder or drive. UTM's source adds it as a shortcut that stays where it is; it is not copied into the container.

On a new Mac, put the copy where you want it and open it. Start it before you delete the original.

Space you can free, and what not to delete

• Delete in a machine's right-click menu deletes the VM and all its data. For a machine opened from elsewhere the item reads Remove instead, and it only removes the shortcut; the files stay.
• Resizing only goes up: UTM's documentation says disk images can be grown but not shrunk, calls resizing experimental, and says to back up first.
• Never delete files inside a .utm package by hand. config.plist refers to the images in Data, and a missing image leaves a machine that cannot start.

Why a normal search misses them

The container is inside ~/Library, which Finder and Spotlight searches leave out, and each machine is a package that looks like one file, so the disk images inside never appear on their own.

Finding a machine again

Type .utm into Everywhere to list every machine package on the Mac, in the container or on a drive you moved one to, or qcow2 to find the disk images inside them. ~/Library/Containers is one of the folders macOS protects, so these appear once Everywhere has Full Disk Access, which also covers external drives. It matches file names only.

Common questions

Where does UTM store virtual machines on a Mac?

In ~/Library/Containers/com.utmapp.UTM/Data/Documents/, one .utm package per machine. This is UTM's sandbox Documents folder, not your own Documents folder.

How do I back up or move a UTM VM?

Shut the VM down, then copy its .utm package, or right-click it in UTM and choose Move... to put it on another drive. Keep the original until the copy starts.

Why is my UTM VM so large?

Disk images grow as the guest writes data and snapshots add more. Check the package with du -sh, delete old snapshots, and for QEMU machines try Reclaim Space in the drive settings after backing up.

Can I keep UTM VMs on an external drive?

Yes. Right-click a machine and choose Move..., or copy the .utm to the drive and open it with File > Open..., which adds it to UTM's list without copying it into the container.