What is a .zst file?
A .zst file is a zstandard archive. Its registered MIME type is application/zstd, which places it in the application or document family of formats.
ZST is a binary format: the contents are not readable text, so opening it in a text editor shows scrambled characters.
Files of this type usually begin with the bytes 28 B5 2F FD. That signature is how programs recognise the format even when the extension is wrong or missing.
ZST file format details
| Extension | .zst |
|---|---|
| Format | Zstandard archive |
| MIME type | application/zstd |
| Category | Application or document |
| Text or binary | Binary |
| File signature | 28 B5 2F FD |
| Registered with IANA | Yes |
| Other extensions | None |
How to open ZST files
| Windows | Windows opens ZIP files itself. For other archive types, the free 7-Zip program opens most of them, ZST included. |
|---|---|
| Mac | Archive Utility opens ZIP and several other formats with a double click. The free app The Unarchiver handles many more. |
| iPhone and iPad | The Files app can open ZIP archives. Other archive types need an app from the App Store. |
| Android | Files by Google opens ZIP archives. Other types need an archive app such as RAR or ZArchiver. |
Can you convert a .zst file?
TapToConvert does not convert ZST files. The usual route is to open the file in the program that made it and use its Export or Save as option.
ZST file FAQ
What is a .zst file?
A .zst file is a zstandard archive, with the MIME type application/zstd.
How do I open a .zst file?
7-Zip on Windows and The Unarchiver on Mac open most archive formats.
Is a .zst file safe to open?
ZST files hold data rather than programs, but any file from an unknown source can be crafted to exploit the software that opens it. Keep that software up to date. The viewer on this page only reads the bytes and never runs anything.
What is the MIME type of .zst?
application/zstd. Web servers send this type so browsers know how to handle the file.
Is ZST a text or binary format?
Binary. Its contents are not readable as text.
File type facts come from the IANA media type registry, the mime-db project and the freedesktop.org shared MIME database.