DMG is macOS's disk image: a UDIF container that can hold an HFS+/APFS filesystem, compression and even encryption. Every Mac app download ships as one.
Typical use: Extract DMG contents to repackage installers or pull files out on any OS — the 7-Zip engine reads the common compressed variants.
About the DMG format
DMG is Apple's Universal Disk Image Format: a UDIF wrapper that can carry an HFS+ or APFS filesystem, ADC/LZFSE/ZLIB compression blocks, and optional AES encryption. It is the distribution vehicle of every macOS application — double-click, drag, done.
The format is officially undocumented, which makes cross-platform extraction historically painful; 7-Zip's decoder handles the common compressed variants, letting any OS pull the payload out and repackage it as a plain ZIP or TAR.
Strengths
- ✓ Native macOS distribution standard
- ✓ Supports compression and encryption
- ✓ 7-Zip reads the common variants in-browser
Limitations
- ✗ Unofficial format — exotic variants may fail
- ✗ Encrypted DMGs need a password
- ✗ APFS volumes are partial-support
- Structure
- UDIF wrapper (koly trailer) + HFS+/APFS
- Types / schema
- Block copy, ADC/LZFSE/ZLIB compressed
- Compatibility
- macOS, 7-Zip, cross-platform tools
- Best for
- Mac application distribution
Convert DMG to…
12 direct directions, sorted A–Z; 🔥 marks popular targets.
Frequently asked questions
What is a DMG file?
DMG is macOS's disk image: a UDIF container that can hold an HFS+/APFS filesystem, compression and even encryption. Every Mac app download ships as one.
How do I convert DMG files online?
Pick a target format from the "Convert DMG to…" list below, drop your file and hit convert. Everything runs in your browser — no install, no upload, no watermark, no limits.
Is it safe to convert DMG files here?
Yes. Every conversion is performed by your own device inside the browser — files never leave for a server, and the page keeps working even offline.
Which formats can DMG convert to?
This page lists all 12 directions across documents, images, audio, video, spreadsheets and archives — each one is its own free converter page.