Code · .pyi

Open a .pyi file online

A .pyi file is Python Type Stub, from Python (PEP 484). You can open one right here, free, without installing anything.

Drop your .pyi file here

or click to choose — you can also paste with Ctrl+V

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Detects the real format · never uploaded · works offline

What is a .pyi file?

Python Type Stub is a source code format developed by Python (PEP 484), first released in 2015. It is usually created by mypy, Pyright, typeshed.

Type signatures only — no implementation — so type checkers understand untyped libraries.

File details

Full namePython Type Stub
CategoryCode
MIME typetext/x-python
DeveloperPython (PEP 484)
Introduced2015
Opens withCode viewer
Uploaded?No — read locally in your browser

How to open a .pyi file

OpenAnyFile routes .pyi files to its code viewer, which shows the source with syntax highlighting.

  1. Drop your .pyi file on the box above, click it to choose the file, or paste it with Ctrl+V.
  2. The real format is detected from the file's first bytes — not just its name.
  3. The file opens in the code viewer.
  4. 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 source with syntax highlighting. 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 .pyi 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 .pyi files

Can I open a .pyi file without installing software?

Yes. OpenAnyFile opens .pyi files in your browser using its code viewer. You get the source with syntax highlighting, with nothing installed and no account.

How do I know a file is really a .pyi file?

Check its first bytes instead of its name. This format has no fixed signature, so the detected type and the readable content are the best clues. OpenAnyFile shows the detected type, so a renamed file is easy to spot.

Is my .pyi 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.

Open a .pyi file now All 822 file types