CONVERT
DMG → ZST
Tap to choose your fileDRAG. DROP. DONE.
Upload any file and our engines will handle format detection automatically.
Max 25 MB · Free plan · No signup required
Convert to:
Detecting available formats...
Optimize for
Leave empty to use original name. Extension added automatically.
Uploading...
Processing your file...
Fast, secure DMG to ZST conversion. No registration required.
Situation. DMG is Apple's Disk iMaGe format for packaging macOS applications and data. Solution: a ZST, produced below. DMG to ZST conversion is the fastest path when the platform or tool you are shipping to does not speak DMG. Instead of asking every recipient to install a decoder, produce a ZST once and hand them something their OS opens natively. Keep in mind DMG is Apple's Disk iMaGe format for packaging macOS applications and data. And remember that ZST is a compression/archive format used to package or shrink files.
Apple Disk Image
Source formatDMG (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.
Zstandard Compressed
Target formatZstandard (Zstd) is a fast lossless compression algorithm developed by Yann Collet at Facebook. It provides compression ratios comparable to zlib while being 3-5x faster at both compression and decompression, making it ideal for real-time data processing.
Why convert DMG to ZST
A ZST often compresses the same content smaller than a DMG at the same strength setting, thanks to more modern codecs. For distribution over bandwidth-limited channels — email, chat apps, CDN delivery — the size difference matters.
HOW TO CONVERT
DMG → ZST
Provide the DMG
Drag-and-drop the archive or pick it from your computer. We accept up to 25 MB on the free tier.
Stream-convert
The DMG is decompressed and re-compressed into ZST in a single pipeline stage — no temporary extracted folder.
Retrieve the output
Click to download the ZST. File structure, timestamps and permissions match the original exactly.
Common Use Cases
Share across platforms
Send ZST files to anyone without worrying about whether they have the right software for DMG.
Embed in documents
Drop ZST output into Word, Google Docs, PowerPoint, Notion or a website without conversion warnings.
Optimize size
ZST often produces smaller files than DMG for web, email and storage.
Archive & future-proof
Store in a widely-supported format that will still open on future operating systems without legacy plugins.
DMG vs ZST — Strengths and limitations
What each format does best, and where it falls short.
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).
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.
ZST Strengths
- Extremely fast decompression (~2 GB/s on modern CPU).
- Scalable: very fast at level 1, near-xz ratios at level 22.
- Dictionary support for small-payload efficiency.
- Multi-threaded by default.
- Standardized (RFC 8478), BSD-licensed reference.
Limitations
- Newer than gzip/bzip2 — some legacy tools still lack support.
- At extreme compression levels, xz can still win on ratio.
- Memory usage at high levels is significant.
DMG vs ZST — Technical specifications
Side-by-side comparison of the technical details.
DMG
- MIME type
- application/x-apple-diskimage
- Extension
- .dmg
- Container types
- UDIF (Universal Disk Image Format)
- Compression
- UDCO (zlib), UDBZ (bzip2), UDZO (LZMA), ULMO (LZMA)
- Encryption
- AES-128 or AES-256
ZST
- MIME type
- application/zstd
- Extension
- .zst
- Algorithm
- LZ77 variant + entropy coding (FSE/Huffman)
- Standard
- RFC 8478 (2018)
- Compression levels
- 1-22 (plus negative "fast" levels)
| Specification | DMG | ZST |
|---|---|---|
| MIME type | application/x-apple-diskimage | application/zstd |
| Extension | .dmg | .zst |
| Container types | UDIF (Universal Disk Image Format) | — |
| Compression | UDCO (zlib), UDBZ (bzip2), UDZO (LZMA), ULMO (LZMA) | — |
| Encryption | AES-128 or AES-256 | — |
| Algorithm | — | LZ77 variant + entropy coding (FSE/Huffman) |
| Standard | — | RFC 8478 (2018) |
| Compression levels | — | 1-22 (plus negative "fast" levels) |
DMG vs ZST — Typical file sizes
Approximate file sizes for common scenarios.
DMG
- Small macOS app 5-30 MB
- Xcode installer ~12 GB
- macOS installer (full) 12-15 GB
ZST
- Default level 3 on source code 28-35% of original
- Level 22 ultra on source code 14-18% of original
- Linux kernel (.tar.zst, level 19) ~130 MB
Quality & Compatibility
Compressed size can go up or down between DMG and ZST depending on the codec and the level — modern LZMA2/Zstd usually beats older Deflate on text, while already-compressed content (images, video) changes little. We default to a balanced level; Advanced options expose the full range.
Tips for Best Results
- If the DMG is password-protected, we will ask for the password during upload; the resulting ZST is emitted with encryption too if the format supports it.
- When the ZST has to fit a strict upload cap, split into multi-volume archives in Advanced — several smaller ZST parts are often accepted where a single large one is rejected.
- For distribution bundles, include a short README at the root of the ZST so recipients know what the archive contains without extracting it.
Frequently Asked Questions
Yes. The free tier accepts files up to 25 MB without registration, email capture or watermarks; paid plans go up to 2 GB. Paid plans raise the size cap, enable batch conversions and provide a REST API for automation, but nothing on the free tier is quality-limited — the output is exactly the same as on any paid plan.
Yes — because DMG and ZST use different compression codecs, every entry is decompressed from the DMG and re-compressed for the ZST. The uncompressed data is identical on both sides, and the re-compression happens entirely inside our processing container.
Uploads run over HTTPS, files are processed in isolated containers, and both the source DMG and the ZST output are auto-deleted within two hours. No account is required, file contents are never logged, and KaijuConverter does not use uploads for AI training. The paid plan adds a signable data-processing agreement for regulated workflows.
Usually yes, modestly, when the original DMG used an older codec like Deflate. Against modern LZMA2 / Zstd ZST containers expect 10-30% savings on mixed content and almost no change on pre-compressed payloads. Advanced → compression level lets you trade speed for ratio.
Most files finish in well under a minute. Small images and documents are typically ready in a few seconds; large video or audio files scale roughly with duration. Upload speed from your network is usually the dominant factor, not server time.
Yes. Provide the password during upload; we use it only to decrypt inside the processing container and never log or persist it. The resulting ZST can be re-encrypted with a password of your choice (AES where the target format supports it).
Related comparisons
See these formats side by side to understand which fits your use case best.
Related Guides
Zstandard & LZ4: The Modern Compression Formats Replacing Gzip
Complete guide to Zstandard (ZST) and LZ4 — the modern compression algorithms replacing Gzip in Linux, Docker, databases, and package managers.
Read guideDMG Format: Apple Mac Disk Images Explained
Complete guide to DMG (Apple Disk Image) files — how DMG works, how to open DMG on Windows or Linux, and how to extract or convert DMG files.
Read guideArchive Formats Compared: ZIP, 7Z, RAR, TAR, and ZSTD
Complete comparison of ZIP, 7-Zip, RAR, TAR.GZ, TAR.XZ, and Zstandard archive formats. Compression ratio, speed, encryption, and when to use each format.
Read guideSecure & Private Conversion
Your files are encrypted during transfer, processed in isolated containers, and automatically deleted within 60 minutes. We never read, share, or store your data.