OpenAnyFile
Works
Viewing, inspecting and verifying. You get a browsable listing of everything inside, decompressed in-browser by libarchive compiled to WebAssembly. File details, exact byte size and the detected signature are always shown.
How to open a .dmg file
If double-clicking a DMG file did nothing useful, that is normal: the format is fine, your operating system just has no default application registered for it. This page explains the format and gives you a way to read one immediately.
What is a .dmg file?
Apple Disk Image is an archive format developed by Apple, first appearing in 1999. It is normally produced by macOS app distribution.
Can be compressed, encrypted and checksummed, and carries a 'koly' trailer at the end rather than a header at the start.
| Full name | Apple Disk Image |
|---|---|
| File category | Archives |
| MIME type | application/x-apple-diskimage |
| Magic bytes (file signature) | 78 01 73 0D 62 62 60 or koly footer |
| Developer | Apple |
| Introduced | 1999 |
| Usually created by | macOS app distribution |
| OpenAnyFile engine | libarchive WASM engine |
| Opens without upload | Yes — parsed locally in your browser |
Open a .dmg file in your browser
OpenAnyFile routes .dmg to its libarchive WASM engine, which opens a browsable listing of everything inside, decompressed in-browser by libarchive compiled to WebAssembly.
- Open the OpenAnyFile opener in this browser — nothing to download or sign up for.
- Drag your .dmg file onto the drop zone, click to browse for it, or paste it with Ctrl+V.
- The extension is detected and the file is handed to the libarchive WASM engine.
- Your DMG opens on its own viewer page: a browsable listing of everything inside, decompressed in-browser by libarchive compiled to WebAssembly.
- Use fullscreen for a closer look, or download the file back out unchanged. Works the same on Windows, macOS, Linux, Android and iOS, because it is just a web page.
What you can and cannot do with it here
Does not work
Editing and re-saving. OpenAnyFile is a reader, not an editor — for changes you still need special software or an equivalent.
Your {ext} file stays on your device
The entire pipeline — detection, decoding, rendering — runs client-side. Your browser hands the bytes to a decoder compiled to WebAssembly, the result is drawn to the page, and that is the whole journey. No account is created, no file is stored, and no analytics event carries your filename. This is also why there is no size limit imposed by a server: the only ceiling is your own available memory.
Frequently asked questions about DMG files
Can I open a .dmg file without installing special software?
Yes. OpenAnyFile's libarchive WASM engine runs in your browser, so you can read a DMG file with nothing installed. You get a browsable listing of everything inside, decompressed in-browser by libarchive compiled to WebAssembly. For full editing you still need the original application — this is a viewer, not an editor.
How can I check a file really is a DMG file?
Look at the first bytes rather than the extension. A genuine DMG begins with 78 01 73 0D 62 62 60 or koly footer. Opening the file in OpenAnyFile shows that signature in the file-details panel, so a file renamed to .dmg by mistake is easy to spot.
Is it safe to open a DMG file online?
With OpenAnyFile, yes, because nothing is uploaded. The file is read locally through your browser's File API and never leaves your device, so there is no server copy to leak, log or retain. That matters most for the kind of file people are least willing to hand to a random converter site.
What is a .dmg file, exactly?
Apple Disk Image — an application/x-apple-diskimage format created by Apple since 1999. Can be compressed, encrypted and checksummed, and carries a 'koly' trailer at the end rather than a header at the start.
Does the same viewer handle formats related to DMG?
Yes — the same engine also opens .7z, .iso, .rar, so you can compare related files without switching tools.
Related formats
These open with the same engine, so if you have one of these sitting next to your .dmg file, it will open too: