O plikach DMG

DMG (Apple Disk Image · Format archiwum)

Rok wydania 1999 Twórca: Apple

Apple Disk Image (.dmg) to standardowy format plików obsługiwany przez KaijuConverter do wymiany danych, archiwizacji i szybkiej konwersji wieloplatformowej.

Kategoria

Archives & Compressed

Rozszerzenie

.dmg

Typ MIME

application/x-apple-diskimage

Dostępny jako

Wejście

Historia powstania

JAK FORMAT DMG
POWSTAŁ.

DMG — Apple Disk iMaGe — replaced the older .img and .sit formats when Apple shipped Mac OS X Server 1.0 in 1999. A .dmg is a read-only, usually compressed disk image that mounts on macOS as if it were a real volume: the user drags the app icon from the mounted volume to the Applications folder and that's the install.

DMGs can be plain disk images, zlib-compressed (UDCO), bzip2-compressed (UDBZ), or LZMA-compressed (UDZO/ULMO). Modern DMGs from Apple’s App Store are ZFS-like compressed variants. Every third-party macOS app distributed outside the App Store ships as a DMG with a custom background, volume icon, and an arrangement arrow telling the user to drag the app into Applications. It’s a signature macOS aesthetic.

CIEKAWOSTKI I
FAKTY.

The custom DMG background with a pointing arrow telling you "drag the app to Applications" is a macOS cultural signature — invented by no one officially, copied by every indie Mac app.

DMG files can be password-protected via AES-128 or AES-256 encryption — the Finder prompts for the password when mounting.

Apple ships all its non-App Store downloads as DMGs: Xcode, Safari beta, macOS installers, Pages/Keynote.

A DMG can contain multiple partitions, EFI boot sectors, and be bootable — Recovery DMGs use this.

The container format is proprietary but documented enough that tools like dmg2img on Linux can extract most DMGs.

ZALETY I
OGRANICZENIA.

Zalety

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).

Ograniczenia

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.

Typowe rozmiary i waga plików

Small macOS app

5-30 MB

Xcode installer

~12 GB

macOS installer (full)

12-15 GB

Specyfikacja techniczna

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

KONWERTUJ Z
DMG

dmg zip dmg 7z dmg tar dmg gz dmg bz2 dmg xz dmg lzma dmg zst dmg lz4

Typowe zastosowania

macOS software distribution, application installers, encrypted disk images