OpenAnyFile
What is a .npy file?
NumPy Array is a data format developed by NumPy, first released in 2007. It is usually created by Python, NumPy, machine learning.
A tiny header describing dtype and shape, followed by raw array bytes. Shape, type and the first values are shown here.
File details
| Full name | NumPy Array |
|---|---|
| Category | Data & science |
| MIME type | application/x-npy |
| Signature (magic bytes) | 93 4E 55 4D 50 59 (\x93NUMPY) |
| Developer | NumPy |
| Introduced | 2007 |
| Opens with | NumPy reader |
| Uploaded? | No — read locally in your browser |
How to open a .npy file
OpenAnyFile routes .npy files to its NumPy reader, which shows the array shape, type and first values.
- Drop your .npy 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 NumPy reader.
- Use fullscreen for a closer look, check its checksums, or download it back unchanged.
What works — and what does not
Works
Viewing and inspecting: the array shape, type and first values. Size, type, signature and checksums are always shown.
Does not work
Editing and saving back. OpenAnyFile is a viewer, not an editor — for changes you still need the original app.
Is it safe to open a .npy 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 .npy files
Can I open a .npy file without installing software?
Yes. OpenAnyFile opens .npy files in your browser using its NumPy reader. You get the array shape, type and first values, with nothing installed and no account.
How do I know a file is really a .npy file?
Check its first bytes instead of its name. A genuine NPY file begins with 93 4E 55 4D 50 59 (\x93NUMPY). OpenAnyFile shows the detected type, so a renamed file is easy to spot.
Is my .npy 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.