OpenAnyFile
What is a .mat file?
MATLAB Data File is a data format developed by MathWorks, first released in 1984. It is usually created by MATLAB, Octave, SciPy.
Version 5 files begin with a readable 116-byte text header naming the platform and date; v7.3 files are HDF5 underneath.
File details
| Full name | MATLAB Data File |
|---|---|
| Category | Data & science |
| MIME type | application/x-matlab-data |
| Signature (magic bytes) | 4D 41 54 4C 41 42 20 35 2E 30 (MATLAB 5.0) |
| Developer | MathWorks |
| Introduced | 1984 |
| Opens with | Universal inspector |
| Uploaded? | No — read locally in your browser |
How to open a .mat file
OpenAnyFile routes .mat files to its universal inspector, which shows a hex view, the detected signature, checksums and any readable text.
- Drop your .mat file on the box above, click it to choose the file, or paste it with Ctrl+V.
- The real format is detected from the file's first bytes — not just its name.
- The file opens in the universal inspector.
- Use fullscreen for a closer look, check its checksums, or download it back unchanged.
What works — and what does not
Works
Viewing and inspecting: a hex view, the detected signature, checksums and any readable text. Size, type, signature and checksums are always shown.
Does not work
A rendered view. This format has no open decoder, so you get a byte-level inspection and readable text instead.
Is it safe to open a .mat file online?
Here, yes — because nothing is uploaded. Most "online viewers" send your file to their server. OpenAnyFile reads it with your browser's File API and decodes it on your own device, so there is no copy anywhere else. You can check: open your browser's network tab while opening a file — no upload appears.
Questions about .mat files
Can I open a .mat file without installing software?
Yes. OpenAnyFile opens .mat files in your browser using its universal inspector. You get a hex view, the detected signature, checksums and any readable text, with nothing installed and no account.
How do I know a file is really a .mat file?
Check its first bytes instead of its name. A genuine MAT file begins with 4D 41 54 4C 41 42 20 35 2E 30 (MATLAB 5.0). OpenAnyFile shows the detected type, so a renamed file is easy to spot.
Is my .mat file uploaded anywhere?
No. The file is read locally by your browser and never sent to a server — it even works offline once the page has loaded.
Does it work on phones?
Yes — on Android and iPhone, in any modern browser. You can also install OpenAnyFile as an app.
Related formats
Other formats from the same family:
Format facts checked and page updated on September 25, 2026.