ODT File Format Explained

OpenDocument Text · .odt

Extension.odt
MIME typeapplication/vnd.oasis.opendocument.text
TypeDocuments
Developed byOASIS
First released2005
Royalty-freeYes
CompressionLossless

What is an ODT file?

ODT is the word-processing format of the OpenDocument standard (ISO/IEC 26300), the native format of LibreOffice Writer and Apache OpenOffice. Like DOCX it is a ZIP package of XML parts: content.xml holds the text, styles.xml the formatting, and a Pictures folder the images. The standard is maintained by OASIS, not by a single vendor.

Governments and public bodies in several countries require OpenDocument for official documents because the specification is open and vendor-neutral. Microsoft Word has opened and saved ODT since Office 2007 SP2, though complex documents may look slightly different between suites.

When ODT is the right choice

Strengths

  • Open, vendor-neutral standard preferred by public administrations
  • Native to LibreOffice; supported by Word, Google Docs and Collabora
  • Same package structure as DOCX: compact, recoverable, inspectable

Limitations

  • Less common than DOCX in business, so recipients may need to convert
  • Tracked changes and advanced layout do not round-trip perfectly with Word
  • Not a fixed final copy; use PDF for that

How to open an ODT file

LibreOffice Writer is the reference application; Microsoft Word, Google Docs and Collabora Online also open ODT. For readers without an office suite, ODT to PDF produces a file that opens in any browser.

How to convert an ODT file

ODT to DOCX hands the document to Word users, ODT to PDF fixes the layout for sharing, ODT to RTF targets legacy editors and ODT to TXT extracts the plain text. From the other side, DOCX to ODT converts Word files into the open format.

Frequently Asked Questions

Can Microsoft Word open ODT files?

Yes, Word has read and written ODT since 2009. Simple documents convert cleanly; complex tables, tracked changes and some field types may need a check after opening.

What is the difference between ODT and DOCX?

Both are ZIP packages of XML. ODT follows the OASIS OpenDocument standard and is the default of LibreOffice; DOCX follows Office Open XML and is the default of Word. Feature sets overlap heavily, but each suite renders its own format most faithfully.

Why do some authorities require ODT?

Because the specification is open and not controlled by one vendor, which is a condition many public procurement rules place on document formats for long-term access.

Will fonts be preserved when I convert ODT to DOCX?

Font names are preserved; the fonts themselves are not embedded unless you enable that in LibreOffice. On a system without the font, Word substitutes a similar one.