What is the VBOX file format?
.vbox files belong to the category of configuration files used by Oracle VM VirtualBox.
Files with the .vbox extension contain the settings of Oracle VM VirtualBox, a free virtualization platform that enables running a virtual machine on practically any host operating system. The complete configuration of the emulated machine is stored in a .vbox file; its contents include:
- the name of the virtual machine, which often corresponds to the emulated operating system,
- the type and version of the guest operating system,
- the amount of RAM and number of virtual CPU cores allocated,
- references to attached virtual disk images (
.vdi,.vmdk, or.vhdfiles stored separately), - settings for network adapters, USB controllers, and other peripheral devices,
- the list of snapshots and startup parameters.
The content of .vbox files is saved using the XML markup language, making them human-readable in any text editor.
Virtual machines supported by VirtualBox allow running operating systems different from the host - for example, a Windows environment on a Mac, or Linux on a Windows PC. They are used for software testing, development, and security sandboxing.
Although .vbox files can technically be opened with even a simple program like Notepad, manual editing is not recommended due to the high level of complexity in the internal XML structure. Inexpert or accidental modification can lead to errors in the operation of the virtual machine, or even prevent it from starting. VirtualBox automatically saves a .vbox-prev backup each time it updates the settings.
Security & safety
RISK: LOWA .vbox is plain XML configuration with no executable code, so the file itself is harmless. Risk comes from the guest OS the VM runs, not the .vbox. Editing the XML by hand can break the VM - close VirtualBox first and keep the .vbox-prev backup.
Format details
in a nutshellFULL NAMEVirtualBox Machine Definitionaka VirtualBox settings file, VirtualBox VM configuration
DEVELOPEROracle Corporationsince 2008 (VirtualBox 2.0 moved VM settings to per-machine .vbox XML files)
CATEGORYSettings Files
MIME TYPEapplication/xml
TYPEXML virtual-machine configuration descriptor (text)
MAGIC BYTES · FILE SIGNATURE
OFFSET
0001020304
HEX
3C3F786D6C
ASCII
<?xml
A .vbox is a UTF-8 XML document beginning with the XML declaration, followed by a <VirtualBox xmlns="http://www.virtualbox.org/" version="..."> root element. No binary signature.
Programs that open VBOX files
Windows2 apps
Oracle VM VirtualBox
Free Double-click the .vbox to register the VM in VirtualBox Manager, then click Start. Or Machine → Add and select the .vbox.
Notepad / any text editor
Open-source Open the .vbox to read or hand-edit the XML (do this only with VirtualBox closed and a backup). 
macOS1 app
Oracle VM VirtualBox
Free Double-click the .vbox, or Machine → Add in VirtualBox Manager to register and launch it. 
Linux1 app
Oracle VM VirtualBox
Free GUI: Machine → Add → select the .vbox. CLI: VBoxManage registervm /path/to/Machine.vbox. Technical details
deep spec| File type | XML virtual-machine configuration descriptor |
| Developer | Oracle Corporation (VirtualBox) |
| Encoding | Text, UTF-8 |
| Container | XML |
| Encryption | None (the VM's attached disk image may be encrypted; the .vbox file itself is plain text) |
| Typical file size | 3 KB - 30 KB |
| Magic bytes | <?xml at offset 0 (standard XML declaration) |
| Root XML element | <VirtualBox xmlns="http://www.virtualbox.org/" version="..."> |
| VM configuration stored | CPU and RAM allocation, storage controllers, attached disk image paths/UUIDs, network adapters, USB, display, and snapshot list |
| Disk images | Referenced by path or UUID only; virtual disk (.vdi, .vmdk, .vhd) is a separate file not embedded in .vbox |
| Schema versioning | version attribute in root element updated per VirtualBox release; .vbox-prev backup created on upgrade |
| MIME type | application/xml |
| Associated OS | Windows, macOS, Linux, Solaris |
| Backup file | .vbox-prev is automatically written by VirtualBox whenever it upgrades the settings schema |
| Released | 2008 (VirtualBox 2.0 moved VM settings to per-machine .vbox XML files) |
| Latest version | Settings schema versioned per VirtualBox release (e.g. version='1.19-...' header attribute) |
| Specification | www.virtualbox.org |
VBOX conversions
Possible
Not possible
Community Q&A
asked by users
M
Frequently asked questions
What is a VBOX file and how do I open it?
It is a VirtualBox virtual-machine configuration in XML. Double-click it to register and start the VM in Oracle VM VirtualBox, or open it in a text editor just to read the settings.
Does the VBOX file contain my virtual machine's disk?
No. It only stores settings and references the disk images (.vdi/.vmdk/.vhd) by path. Copying just the .vbox moves the configuration but not the operating system or data.
How do I move a VirtualBox VM to another computer?
Export it to an .ova file (File → Export Appliance), which bundles the .vbox settings with the disks, then import that on the other machine. Don't copy the .vbox alone.
What is the .vbox-prev file next to my .vbox?
It is an automatic backup of the previous settings VirtualBox made before the last change. If a bad edit breaks the VM, rename it back to .vbox to restore.
Is VBOX the same as the VirtualBox extension pack (.vbox-extpack)?
No. A .vbox defines one VM; a .vbox-extpack is a host add-on that adds features like USB 3.0 to the VirtualBox program itself.
My VM disappeared from VirtualBox - how do I get it back?
In VirtualBox Manager choose Machine → Add and select the VM's .vbox file to re-register it.
References
1VirtualBox Manual - VBoxManage and configurationwww.virtualbox.org
2VirtualBox Manual - Technical background (settings)www.virtualbox.org
