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 .zst file
ZST files come from Arch Linux packages, databases, and the usual advice — buy the software that made it — is rarely what you need just to look inside one. This page covers what the format is and how to open it in a browser tab.
What is a .zst file?
Zstandard Compressed File is an archive format developed by Facebook / Meta, first appearing in 2016. It is normally produced by Arch Linux packages, databases.
Reaches near-gzip ratios at many times the speed, which is why Arch, Fedora and Btrfs adopted it for transparent compression.
| Full name | Zstandard Compressed File |
|---|---|
| File category | Archives |
| MIME type | application/zstd |
| Magic bytes (file signature) | 28 B5 2F FD |
| Developer | Facebook / Meta |
| Introduced | 2016 |
| Usually created by | Arch Linux packages, databases |
| OpenAnyFile engine | libarchive WASM engine |
| Opens without upload | Yes — parsed locally in your browser |
Open a .zst file in your browser
OpenAnyFile routes .zst 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 .zst 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 ZST 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 ZST files
Can I open a .zst file without installing special software?
Yes. OpenAnyFile's libarchive WASM engine runs in your browser, so you can read a ZST 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 ZST file?
Look at the first bytes rather than the extension. A genuine ZST begins with 28 B5 2F FD. Opening the file in OpenAnyFile shows that signature in the file-details panel, so a file renamed to .zst by mistake is easy to spot.
Is it safe to open a ZST 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 .zst file, exactly?
Zstandard Compressed File — an application/zstd format created by Facebook / Meta since 2016. Reaches near-gzip ratios at many times the speed, which is why Arch, Fedora and Btrfs adopted it for transparent compression.
Does the same viewer handle formats related to ZST?
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 .zst file, it will open too: