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.OTT file extension

To open .OTT files on Windows, install or open LibreOffice, then use File  Open and select the .OTT file.

To open a .OTT file, use an OpenDocument-compatible office suite such as LibreOffice or Apache OpenOffice. An .OTT is a template (not a normal document), so opening it typically lets you create a new document based on that template.

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Last updated: June 10, 2026

Open on your device

Choose your operating system for a dedicated step-by-step opening guide.

How to open .OTT files

Use these platform-specific instructions to open .OTT files safely.

Windows

  1. Install or open LibreOffice, then use File  Open and select the .OTT file.
  2. If it opens as a template, use File  New  Templates (or create a new document from the template) to produce an editable document based on it.
  3. Alternatively, open it with Apache OpenOffice (Writer) using File  Open.
Full Windows guide

Mac

  1. Install or open LibreOffice, then use File  Open and select the .OTT file.
  2. If you want a normal document from it, create a new document from the template and then save as an .ODT (or your preferred format).
Full Mac guide

Linux

  1. Open LibreOffice, then choose File  Open and select the .OTT file.
  2. To use it as intended, create a new document from the template rather than overwriting the template itself.
Full Linux guide

iOS

  1. There is no broadly reliable, native iOS support for editing .OTT templates; if the file won’t preview, transfer it to a desktop and open it with LibreOffice or Apache OpenOffice.
Full iOS guide

Android

  1. Android support for editing .OTT templates is not consistently available; if your office app can’t open it, transfer the file to a desktop and open it with LibreOffice or Apache OpenOffice.
Full Android guide

Security notes

  • .OTT is an office document template format; treat templates from unknown sources cautiously because they can influence document content and formatting users may trust.
  • Prefer opening untrusted .OTT files in a viewer or a sandboxed environment first; office document parsers can have vulnerabilities, and templates can be used for social-engineering (e.g., convincing-looking invoices or forms).
  • If your office suite offers options related to macros or active content, keep them disabled unless you fully trust the file source and understand what the template contains.

Can't open this file?

These are the most common causes and fixes when .OTT files fail to open.

Common reasons

  • The file opens, but I can’t edit it like a normal document
  • .OTT file does not open or shows an error
  • Formatting looks wrong when opened in a different suite

Fix steps

  1. In LibreOffice/OpenOffice, open the .OTT and use the template workflow (create a new document from it).
  2. Save the newly created document as .ODT (or another format) to edit it as a normal document.

Recover a deleted or lost .OTT file

If the file was deleted by mistake or the drive was formatted, data recovery software may be able to get it back. Stop writing to that drive right away, because new data can overwrite what you want to recover.

MiniTool Power Data Recovery

Windows software that recovers deleted or lost files from PCs and external drives such as HDDs, SSDs, USB drives and memory cards, after deletion, formatting or a crash.

Wondershare Recoverit

Windows and Mac software that recovers deleted or lost files from computers and external drives such as HDDs, SSDs, USB drives and SD cards.

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OS-specific troubleshooting

What is a .OTT file?

.OTT is the OpenDocument Format (ODF) text template file type. It is associated with the registered media type application/vnd.oasis.opendocument.text-template. In practice, it stores a reusable text-document template (styles, page layout, default content) for generating new documents.

Background

OTT belongs to the OASIS OpenDocument Format (ODF) family, an open standard for office documents. Within ODF, .ott specifically represents a text template (as opposed to a regular text document, which is commonly .odt).

Templates are used to keep formatting consistent across many documents—such as letterheads, reports, forms, and branded documents—by embedding predefined styles, layout settings, and optional placeholder text.

This file type is widely supported by ODF-focused office suites. LibreOffice documents its support for “ODF Text Template (*.ott)”, and Apache OpenOffice lists the same association for type detection and MIME mapping.

Common MIME types: application/vnd.oasis.opendocument.text-template

Further reading

Authoritative resources for more details on the .OTT format.

Common .OTT issues

The file opens, but I can’t edit it like a normal document

.OTT is a template format, so the expected workflow is to create a new document based on the template rather than editing the template as if it were a standard document.

  1. In LibreOffice/OpenOffice, open the .OTT and use the template workflow (create a new document from it).
  2. Save the newly created document as .ODT (or another format) to edit it as a normal document.

.OTT file does not open or shows an error

This often happens when no ODF-capable office suite is installed, the file is corrupted/incomplete, or the file is not actually an ODF text template despite the extension.

  1. Open the file in LibreOffice (which explicitly supports ODF Text Template *.ott) or Apache OpenOffice.
  2. Re-download or re-copy the file to ensure it is complete and not truncated.
  3. If possible, ask the sender to re-export or resend the template in ODF (.ott) to avoid mismatched extensions.

Formatting looks wrong when opened in a different suite

ODF is standardized, but template styling and layout can still vary slightly between implementations or versions.

  1. Open and test the template in the same suite it was created in (often LibreOffice or Apache OpenOffice).
  2. If you maintain the template, adjust styles to more standard ODF constructs and re-save the .OTT.
  3. When distributing, provide a reference PDF in addition to the template so recipients can verify expected appearance.

FAQ

What does .OTT stand for?

It commonly refers to an OpenDocument Text Template: a template used to create new text documents with predefined styles and layout.

Is an .OTT file the same as an .ODT file?

No. .OTT is a template used to create new documents; .ODT is typically a regular text document. You usually create a new document from the .OTT and then save the result as .ODT.

What is the MIME type for .OTT?

application/vnd.oasis.opendocument.text-template (registered in the IANA media types registry and referenced by ODF documentation).

Can I convert a file to .OTT by renaming the extension?

No. Renaming only changes the filename; use your office suite’s Save As/Export options to create a real ODF text template.

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