Ext Decoder
Disk Image

.dmg — Apple Disk Image

macOS's native disk image format, most commonly used to distribute and install Mac applications.

Commonly opened with
  • Disk Utility (macOS, built-in)
Supported platforms
  • macOS
Editable?
Not really — it's a runnable or packaged format
Viewable without special tools?
Usually, yes
Commonly converted to
  • .iso
Inherent format risk
Use some caution
Safety guidance (not a guarantee)

Disk images can contain an entire file system, including installers or executables. Treat the contents with the same caution you'd give any downloaded software.

Check another filename

No upload, no sign-up — everything is analyzed locally in your browser.

Frequently asked questions

What is a .dmg file?

macOS's native disk image format, most commonly used to distribute and install Mac applications.

Can I edit a .dmg file?

Not directly as text — .dmg is a runnable or packaged format, not one meant for manual editing.

Does having a .dmg extension mean the file is safe?

No single extension can guarantee that. Disk images can contain an entire file system, including installers or executables. Treat the contents with the same caution you'd give any downloaded software. Always consider where the file came from, not just its name.

Privacy: The lookup above runs entirely in your browser. Nothing you type is uploaded, logged, or sent anywhere.

← Back to the file extension lookup tool