OpenAnyFile
What is a .ott file?
OpenDocument Text Template is a document format developed by OASIS, first released in 2005. It is usually created by LibreOffice Writer.
The ODT template counterpart — same package, different mimetype entry in the ZIP.
File details
| Full name | OpenDocument Text Template |
|---|---|
| Category | Documents |
| MIME type | application/vnd.oasis.opendocument.text-template |
| Signature (magic bytes) | 50 4B 03 04 (PK..) |
| Developer | OASIS |
| Introduced | 2005 |
| Opens with | Document text extractor |
| Uploaded? | No — read locally in your browser |
How to open a .ott file
OpenAnyFile routes .ott files to its document text extractor, which shows the full text in reading order.
- Drop your .ott 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 document text extractor.
- 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 full text in reading order. Size, type, signature and checksums are always shown.
Does not work
Original layout and styling. The text is extracted; fonts, positioning and page design are not reproduced.
Is it safe to open a .ott 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 .ott files
Can I open a .ott file without installing software?
Yes. OpenAnyFile opens .ott files in your browser using its document text extractor. You get the full text in reading order, with nothing installed and no account.
How do I know a file is really a .ott file?
Check its first bytes instead of its name. A genuine OTT file begins with 50 4B 03 04 (PK..). OpenAnyFile shows the detected type, so a renamed file is easy to spot.
Is my .ott 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.