ODT vs DOCX: Which Document Format Should You Use?
Published on March 15, 2026
ODT is an open standard maintained by OASIS and used by LibreOffice, OpenOffice, and Google Docs. DOCX is Microsoft's format, default in Word since 2007. Both store text, images, and formatting. The difference comes down to which software you and your recipients use.
File Structure
Both ODT and DOCX are ZIP archives containing XML files. ODT uses the OpenDocument Format (ODF) specification, while DOCX uses Office Open XML (OOXML). The XML schemas differ, but the concept is identical: structured content separated from styling. Because both are open and documented, third-party software can read and write either format. In practice, DOCX support is more widespread because Microsoft Office dominates the market.
Compatibility
DOCX works perfectly in Microsoft Word, Google Docs, Apple Pages, and LibreOffice. ODT works perfectly in LibreOffice, OpenOffice, and Google Docs, but Microsoft Word's ODT support has quirks. Complex formatting, tables, and embedded objects sometimes shift when opening ODT files in Word. If you are collaborating with people who use Word (which is most office environments), DOCX causes fewer headaches.
Features and Formatting
DOCX supports every Word feature: track changes, SmartArt, content controls, advanced table styles, and macros (via DOCM). ODT supports a similar feature set through the ODF standard, but some Word-specific features like certain chart types or form controls have no direct ODT equivalent. When converting between formats, these features may be lost or degraded. For basic documents with text, headings, images, and tables, both formats are functionally identical.
File Size
File sizes are comparable. Both formats compress their XML content with ZIP. A typical 10-page document with a few images will be roughly the same size in either format. ODT files are sometimes marginally smaller because the ODF schema is simpler, but the difference is negligible for normal documents.
Which to Choose
Use DOCX if you work in an environment where Microsoft Office is standard, which covers most businesses, schools, and government offices. Use ODT if you prefer open-source software and your collaborators also use LibreOffice or OpenOffice. If you are sharing a document that nobody needs to edit, convert it to PDF instead. Our Word to PDF converter handles DOCX files directly in your browser.
Related reading: DOC vs DOCX explains the older Word binary format, PDF vs DOCX compares document sharing formats, and CSV vs XLSX covers a similar open-vs-proprietary choice for spreadsheets, and Pages vs DOCX compares Apple Pages with Microsoft Word. If you are deciding between a word processor and a typesetting system, see LaTeX vs Word.