DMG vs XZ
A detailed comparison of Apple Disk Image and XZ Compressed — file size, quality, compatibility, and which format to choose for your workflow.
Apple Disk Image
Archives & CompressedDMG (Apple Disk Image) is the standard disk image format on macOS for distributing software. It can contain a complete file system with compression and optional encryption, and supports internet-enabled auto-mounting for seamless app installation.
About DMG filesXZ Compressed
Archives & CompressedXZ provides very high compression ratio using LZMA2, common in Linux packages.
About XZ filesStrengths Comparison
DMG Strengths
- Universal macOS distribution format since 1999.
- Compressed or encrypted variants available.
- Can be bootable (used by recovery and installer DMGs).
- Custom backgrounds and layout create polished installer experience.
- Preserves Mac-specific filesystem metadata (extended attributes, resource forks).
XZ Strengths
- Best-in-class compression ratio among mainstream tools.
- Streaming-capable — can pipe through network.
- Multi-threaded compression available.
- Mature on every Linux distribution.
- Supports integrity checking (CRC32, CRC64, SHA-256).
Limitations
DMG Limitations
- macOS-only — Windows and Linux need third-party tools.
- Proprietary container with limited public documentation.
- File sizes are often larger than equivalent ZIP or 7z.
- Opaque to most antivirus and malware-scanning pipelines.
XZ Limitations
- Slow compression at high levels — 3-5× slower than gzip.
- Memory-hungry: xz -9 can need 700+ MB to compress.
- 2024 supply-chain backdoor damaged trust in the project.
- Zstandard outperforms xz at similar ratios with less memory.
Technical Specifications
| Specification | DMG | XZ |
|---|---|---|
| MIME type | application/x-apple-diskimage | application/x-xz |
| Extension | .dmg | — |
| Container types | UDIF (Universal Disk Image Format) | — |
| Compression | UDCO (zlib), UDBZ (bzip2), UDZO (LZMA), ULMO (LZMA) | — |
| Encryption | AES-128 or AES-256 | — |
| Extensions | — | .xz, .txz |
| Algorithm | — | LZMA2 |
| Standard | — | The .xz File Format specification 1.1.0 |
| Integrity checks | — | None, CRC32, CRC64, SHA-256 |
Typical File Sizes
DMG
- Small macOS app 5-30 MB
- Xcode installer ~12 GB
- macOS installer (full) 12-15 GB
XZ
- Text/source archive 15-25% of original
- Linux kernel (.tar.xz) ~125 MB
- Firefox source code ~600 MB
Ready to convert?
Convert between DMG and XZ online, free, and without installing anything. Encrypted upload, automatic deletion after 60 minutes.
Frequently Asked Questions
DMG (Apple Disk Image) is an archive format used to bundle multiple files and folders into a single compressed file. The archive preserves the directory structure and typically reduces total size via compression. DMG sits in the archives & compressed family and has specific strengths around compression ratio, speed, or platform support.
DMG (Apple Disk Image) is an archive formato used to bundle multiple arquivos e folders em a single comprimido file. The archive preserves the directory structure e tipicamente reduces total size via compressão. DMG sits no archives & comprimido family e has specific strengths around compressão ratio, speed, ou plataforma support.
7-Zip, WinRAR, The Unarchiver (macOS), and the built-in archive utilities on Windows and macOS open most DMG files. For command-line extraction, 7z, unar, or the format-specific tool handles DMG cleanly. If your extractor does not recognise DMG, convert to ZIP first — ZIP opens on every operating system without extra software.
7-Zip, WinRAR, The Unarchiver (macOS), e the built-in archive utilities no Windows e macOS abrir most DMG files. para command-line extraction, 7z, unar, ou the formato-specific tool handles DMG cleanly. If your extractor does not recognise DMG, converter to ZIP first — ZIP opens on every operating system sem extra software.
Upload the DMG to KaijuConverter and pick ZIP, 7Z, TAR.GZ, or RAR as the target. Our pipeline extracts the original archive and re-compresses the contents into the target format. File permissions, timestamps, and directory structure are preserved where both formats support them.
Depends on the goal. ZIP is the universal baseline — every OS extracts it out of the box. Formats like 7Z or TAR.GZ compress better but require specific tools. DMG may win on compression ratio, password support, or OS integration for specific workflows; ZIP wins on raw compatibility.