What is the ODT file format?
Files with the .odt extension (OpenDocument Text) are editable word-processing documents belonging to the Open Document Format (ODF) family. The format is maintained by OASIS as an open standard and ratified as ISO/IEC 26300. Within the ODF family, .odt is the primary text-document type; companion formats include .ods for spreadsheets and .odp for presentations.
Structurally, .odt files are stored as ZIP archives, so renaming one to .zip and unpacking it reveals a folder of XML files. Every valid .odt package contains at least these core components:
mimetype- a single uncompressed entry holding the stringapplication/vnd.oasis.opendocument.text, placed first so the MIME type is readable without decompressing the archivecontent.xml- the document body and basic style referencesstyles.xml- full style definitions covering text orientation, spacing, and page layoutmeta.xml- document metadata such as author, title, and last-modification datesettings.xml- application-specific settings such as window size and zoom levelMETA-INF/manifest.xml- an index listing every file inside the package
Support for .odt files
.odt is natively supported by LibreOffice Writer and Apache OpenOffice Writer, which treat it as their default save format. Microsoft Word (2013 and later) can open and save .odt files directly, with noticeably improved fidelity in Word 2016 and Microsoft 365 compared with earlier versions. ONLYOFFICE Desktop Editors provides strong round-trip compatibility. Google Docs can both import and export .odt files. AbiWord and Collabora Office (available on Android and iOS) also offer solid support.
A flat, single-file XML variant exists as .fodt, which stores the same content without ZIP compression - useful for version control and plain-text diffing.
Security & safety
RISK: LOWODT files are generally safe documents, with the caveat shared by all office formats: they can contain macros (LibreOffice Basic), which both LibreOffice and Word block or prompt about by default - never enable macros in a document you did not expect. Embedded hyperlinks and OLE objects can point to malicious destinations, and ODT has occasionally appeared in spam campaigns because mail filters scrutinize it less than DOCM. Opening an ODT with macros disabled is safe.
Format details
in a nutshellFULL NAMEOpenDocument Text
DEVELOPEROASIS (originated at Sun Microsystems / OpenOffice.org)since 2005 (ODF 1.0, OASIS); ISO/IEC 26300 since 2006; current major version ODF 1.3 (OASIS, 2021)
CATEGORYText Files
MIME TYPEapplication/vnd.oasis.opendocument.text
TYPEZIP-based package of XML files
STANDARDOpen · royalty-free
MAGIC BYTES · FILE SIGNATURE
OFFSET
00010203
HEX
504B0304
ASCII
PK··
Like any ZIP; the first archive entry is an uncompressed file named "mimetype" containing "application/vnd.oasis.opendocument.text", so the MIME string is readable in plain bytes starting around offset 38
Programs that open ODT files
Windows4 apps
Microsoft Word
Paid Open directly (File - Open) - ODT supported since Word 2007, ODF 1.3 in Microsoft 365. Saving back as ODT may drop Word-only features; Word warns when it does. 
LibreOffice Writer
Open-source ODT is its native format - double-click after installing. The reference implementation; full fidelity. 
Apache OpenOffice Writer
Open-source Opens ODT natively, but the project receives only sporadic maintenance (still ODF 1.2) - LibreOffice is the actively developed choice.
ONLYOFFICE Desktop Editors
Open-source Free desktop suite; opens and edits ODT, saves to ODT or DOCX. 
macOS2 apps
Microsoft Word for Mac
Paid Opens ODT like the Windows version. Note: Apple's Pages can import ODT but with formatting loss. 
Linux2 apps
AbiWord
Open-source Lightweight word processor; opens ODT for quick viewing/editing (less complete than LibreOffice on complex layouts). 
Android2 apps
Collabora Office
Open-source LibreOffice-based mobile app; opens and edits ODT with desktop-grade fidelity.
iOS1 app
Web2 apps
Google Docs
Free Upload the .odt to Google Drive and open - it converts to a Docs document; download back as .odt or .docx via File - Download.
Microsoft 365 for the web (Word)
Free Upload to OneDrive and open in Word for the web with a free Microsoft account. Technical details
deep spec| Container format | ZIP archive with Deflate-compressed entries |
| Primary structure files | content.xml, styles.xml, meta.xml, settings.xml, META-INF/manifest.xml |
| MIME type | application/vnd.oasis.opendocument.text |
| Magic bytes | 50 4B 03 04 (ZIP local file header); mimetype entry readable in plain bytes at approximately offset 38 |
| Text encoding | UTF-8 throughout all XML files inside the package |
| Uncompressed entry rule | The mimetype file must be the first ZIP entry and stored without compression, per ODF specification requirement |
| Embedded images | Stored in a Pictures/ subfolder inside the ZIP package |
| Style architecture | Named styles defined in styles.xml; automatic (per-element) styles generated inline in content.xml |
| Change tracking | Revision marks recorded via text:tracked-changes elements in content.xml |
| Macro storage | Built-in Basic macros stored in a Basic/ subtree inside the package |
| Mathematical formulas | MathML-based objects embedded as ODF formula sub-documents and referenced from content.xml |
| Digital signatures | XMLDSig signatures stored in META-INF/documentsignatures.xml |
| Flat unzipped variant | .fodt - single XML file containing all content inline with no ZIP wrapper |
| Template format | .ott (OpenDocument Text Template) uses the same internal XML structure |
| Bidirectional text | RTL and mixed-direction text supported via the writing-mode style property |
| Released | 2005 (ODF 1.0, OASIS); ISO/IEC 26300 since 2006; current major version ODF 1.3 (OASIS, 2021) |
| Open standard | Yes · royalty-free |
| Specification | www.oasis-open.org |
ODT conversions
Possible
.ODT .DOCXGUIDE
Yes - open the ODT in LibreOffice Writer and use File > Save As > Word 2007-365 (.docx); it takes about 10…
How to convert
.ODT .PDFGUIDE
Yes -- open the ODT in LibreOffice Writer and use File > Export as PDF. No third-party tool needed.
How to convert
.ODT .EPUBGUIDE
Yes - LibreOffice Writer exports ODT to EPUB directly, no third-party tool needed.
How to convert
.ODT .DOCGUIDE
Yes - open the ODT in LibreOffice Writer or Microsoft Word, then Save As Word 97-2003 (.doc).
How to convert
.ODT .RTFGUIDE
Yes - open the ODT in LibreOffice Writer or Microsoft Word and use Save As to choose Rich Text Format (.rtf).
How to convert
.ODT .TXTGUIDE
Yes - open the ODT in LibreOffice Writer or Microsoft Word, then Save As Plain Text (.txt). LibreOffice is…
How to convert
.ODT .GDOCGUIDE
Upload your ODT to Google Drive and open it with Google Docs - that is the only step needed.
How to convert
.ODT .HTMLGUIDE
Yes - open the file in LibreOffice Writer and use File > Save As > HTML Document.
How to convert
.ODT .OTTGUIDE
Yes - open the ODT in LibreOffice Writer and use File > Templates > Save as Template (or Save As with the…
How to convert
Not possible
Community Q&A
asked by users
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Frequently asked questions
Can Microsoft Word open ODT files?
Yes - every Word since Word 2007 opens and saves ODT, and Microsoft 365 supports the current ODF 1.3. Complex features may not survive a round trip, and Word shows a compatibility notice when saving.
How do I convert ODT to DOCX?
Open the file in LibreOffice, Word or Google Docs and save/download as .docx. For many files at once: 'soffice --headless --convert-to docx *.odt'.
What is the difference between ODT and DOCX?
Both are ZIP+XML word-processing formats. ODT is the vendor-neutral ISO 26300 OpenDocument standard (native to LibreOffice); DOCX is Microsoft's OOXML (native to Word). Word features go deeper in DOCX; ODT guarantees independence from one vendor.
How do I open an ODT file without installing anything?
Upload it to Google Drive and open with Google Docs, or to OneDrive and open with Word for the web. Both are free in any browser.
Is ODT the same as a Word document?
No. ODT is the OpenDocument Text standard used by LibreOffice/OpenOffice; Word merely supports it alongside its own DOCX format. They're different formats that both editors can read.
Why does Word warn me when saving as ODT?
Word checks for features that ODF stores differently or not at all (certain fields, layout, VBA macros) and warns they may change. Ordinary text, styles and tables convert fine; keep a .docx copy if you rely on advanced features.
References
1ISO/IEC 26300 - OpenDocument Formatwww.iso.org
2OASIS OpenDocument Technical Committee (ODF specifications)www.oasis-open.org
