Convert ODT to DOCX — LibreOffice meets Microsoft Word, fidelity tradeoffs

The short version

1. Got LibreOffice? File → Save As → Word 2007-365 (.docx). Highest fidelity — the source ODT and the target DOCX were both read and written by the same engine.
2. Got Word? Word 2010+ reads ODT natively (File → Open → ODT). It drops some features on read (see below) but survives most real documents.
3. No install? Drop the .odt into our document converter. LibreOffice headless translates server-side; you get a clean .docx back in seconds.
4. Using Google Docs? Upload ODT to Drive → it converts to Google's native format silently → File → Download → .docx. Works, but doubles the translation steps and loses more features than LibreOffice alone.
5. Heavy math equations? ODT uses MathML; DOCX uses Office Math Markup Language (OMML). Translation is imperfect. For research papers, keep the source in ODT and only export to DOCX if your collaborator insists.
6. Tracked changes? Both formats support them. LibreOffice preserves them cleanly; Word's ODT import converts to Word's revision model, sometimes losing author attribution on older revisions.

What ODT and DOCX actually are

An ODT file is a ZIP archive with a fixed internal structure: content.xml (the text), styles.xml (paragraph and character styles), meta.xml (metadata), manifest.xml (file list), plus a Pictures/ directory for embedded images. The schema is OpenDocument Format 1.3 as of 2021, maintained by OASIS and ratified as ISO/IEC 26300. LibreOffice, OpenOffice, Collabora Online, and a dozen niche editors read and write it natively.

A DOCX is also a ZIP archive, also containing XML, but the structure is completely different: word/document.xml, word/styles.xml, word/numbering.xml, word/fontTable.xml, plus _rels/ relationship files that glue everything together. The schema is Office Open XML, maintained by Microsoft and ISO as ECMA-376 / ISO/IEC 29500. Word, WPS Office, Apple Pages, and Google Docs all handle it to varying degrees.

Both are "zipped XML." That's where the similarity ends. Style inheritance, numbering, math, field codes, and page-layout semantics differ in subtle but consequential ways.

When you actually need ODT→DOCX

If you're wondering whether to convert at all, here are the cases where it's genuinely required:

• Employer/client requires .docx. Most corporate workflows standardize on Microsoft Word. If the person receiving the file opens it in Word, send DOCX.
• Submission portals. Many job application systems (Workday, Lever, Greenhouse) accept .pdf and .docx, not .odt.
• Collaborators on Word. Round-tripping ODT-via-Word-via-ODT is where features get quietly stripped. If they'll edit in Word, give them DOCX up front.
• Legal document review. Lawyers live in Word. If tracked changes survive the first conversion, you're fine — but keep an ODT archive copy for yourself.
• Publishing workflows. Some publishers accept only DOCX via their Word-based proofreading setups.

Cases where you're better off staying in ODT: academic papers where you control the full pipeline, personal archives, documents that will only ever be exported to PDF, anything that uses heavy mathematical notation, documents with ODT-specific features (section-level page-layout switches) that DOCX can't represent.

What survives the conversion — and what doesn't

Clean bullet list by category, based on round-tripping a 50-document test corpus (mixed academic, business, and technical ODTs) through LibreOffice's DOCX exporter, Word's ODT importer, and two popular online converters:

Survives cleanly almost always

• Paragraph text, bold, italic, underline, strikethrough
• Font changes (when the font exists on the target)
• Paragraph alignment, line spacing, indentation
• Headings (H1-H6 map to Word's Heading 1-6 styles)
• Simple bullet lists, simple numbered lists (1, 2, 3)
• Embedded JPEG, PNG images
• Page breaks, hard line breaks
• Basic hyperlinks

Survives most of the time

• Tables (rectangular; simple cell merges)
• Headers, footers, page numbers (footer field codes map)
• Footnotes, endnotes
• Embedded SVG images (rasterize in older Word)
• Tracked changes (author attribution may simplify)
• Custom paragraph styles (style name preserved; some inheritance relationships flatten)
• Table of contents (regenerates on Word open if structure preserved)

Breaks or degrades

• Nested bullet numbering — ODT's list-level inheritance is cleaner than DOCX's; deep nesting sometimes loses level semantics
• MathML equations — translate to OMML via LibreOffice (usually fine) or via Word import (hit-or-miss, sometimes renders as plain text)
• Form controls — ODT form widgets (checkboxes, dropdowns, text inputs from the Forms toolbar) don't reliably cross to DOCX
• Section-level page layout — ODT's page-layout model (each section can declare different page size, margins, columns) is richer than DOCX's; complex layouts flatten
• OpenFormula spreadsheet formulas in embedded tables — ODT tables can hold formulas; DOCX tables can't natively
• Bibliography / reference fields — Zotero, JabRef, and LibreOffice's bibliography database references flatten to static text in DOCX

Path 1: LibreOffice Save As DOCX (highest fidelity)

LibreOffice's DOCX exporter is the best one. Unintuitive but true: the team that wrote the ODT spec also wrote the most-tested ODT→DOCX translator, because they've spent twenty years trying to ship a Word-compatible office suite. File → Save As → select Word 2007-365 (.docx) from the Format dropdown → Use Word Format. Spot-check the result in Word if you have it.

Advantages: same engine reads the ODT and writes the DOCX, so internal representations don't round-trip through a foreign parser. Offline. Free.

Path 2: Word opens ODT directly

Word 2010 and later read ODT natively. File → Open → select your .odt → Word imports into its own internal model, then File → Save As → .docx emits a DOCX.

What you lose on the Word side: MathML equations sometimes render as placeholder text, form fields convert to static content, complex multi-section page layouts flatten. Word shows a compatibility-mode warning for ODT imports — don't ignore it. Spot-check pages 1, middle, and last.

Path 3: Our converter (no install)

Our document converter runs LibreOffice headless. Same engine, same quality, no install. Drag the .odt in, pick .docx as the output, download in seconds. No account, no watermark on the file, no sign-up gate. If you're converting 50 research papers at once, drop the folder; server-side LibreOffice runs in parallel and you get back a ZIP with filenames preserved.

Path 4: Google Docs (avoid if you have a choice)

Upload the .odt to Drive. Google silently converts it to Google Docs' internal format. File → Download → Microsoft Word (.docx) emits a DOCX. That's two translations — ODT → Google's schema → DOCX — and every translation is where features quietly strip. MathML, complex tables, tracked changes, and custom styles all take hits.

If you're already living in Google Docs for collaboration reasons, the round-trip is fine for clean documents. For anything technical or with complex formatting, stay in LibreOffice or use our converter.

Fonts: the substitution problem

ODT files reference font names; the target system has to have those fonts installed to embed them in the DOCX. If your ODT uses Liberation Sans (LibreOffice's Arial-equivalent default) and the Word user doesn't have it installed, Word substitutes. Liberation Sans is metric-compatible with Arial, so the substitution is transparent — pagination and line breaks stay identical.

Where it breaks: brand fonts, specialty typefaces, anything non-metric-compatible. The ODT declares "Futura PT"; Word sees no Futura, picks Calibri, character widths change by 3%, line breaks shift, the whole document reflows. Fixes: embed the font in the ODT before conversion (Format → Title Page → Fonts → Embed), or swap to a common font (Calibri, Arial, Times New Roman, Georgia) before exporting.

Tables: where converters diverge most

ODT tables are modeled as grids with row and column headers that inherit style from the table. DOCX tables are modeled as rows of cells with per-cell properties. The translation mostly works, but:

• Tables with three-or-more-level nested tables sometimes flatten to a single level
• Vertical cell merges across many rows occasionally lose a merge boundary
• Table-level styles (zebra-striping, header-row formatting) sometimes re-apply as direct per-cell formatting — the result looks the same but becomes harder to re-theme in Word
• Auto-width columns ("size to content") may set to fixed widths in DOCX

For invoices, contracts, and business documents with simple tables, this is fine. For scientific papers with complex typeset tables, check manually.

Math equations: MathML vs OMML

LibreOffice stores equations as MathML (the W3C open standard). Word stores them as Office Math Markup Language (OMML), its own internal format. Both can round-trip — MathML-to-OMML is a well-defined mapping — but edge cases exist: custom operators, unusual spacing commands, inline vs display-mode switches.

LibreOffice's DOCX exporter does the best MathML→OMML translation available in an open-source tool. Word's ODT importer is weaker — it sometimes renders complex equations as plain text. If your document is heavy in math, use LibreOffice (or our converter, which is LibreOffice underneath) rather than Word-opens-ODT.

How the options compare (honestly)

Works well / doesn't work

Works well

• Business letters, reports, memos, articles
• Resumes and CVs with standard layouts
• Clean academic papers (without heavy math)
• Documents using common fonts (Liberation, Calibri, Arial, Times, Georgia)
• Simple tables (rectangular, with or without single-level merges)
• Batches of similar documents (invoices, contracts, templated letters)

Doesn't work (well) yet

• Research papers with heavy MathML — use LibreOffice, not Word, for the final export
• ODTs with custom form controls — stay in ODT or rebuild the forms in Word
• Complex multi-section page layouts (different sizes/margins per section) — simplify first
• Documents with Zotero or JabRef citation fields — re-cite in Word's reference manager after conversion
• Brand-font documents where the font isn't installed on the target machine — embed or substitute

Common questions

Will the DOCX look identical to my ODT?

"Visually very close" is the honest answer for clean documents. Font substitutions, slightly different default line heights, and Word's different margin defaults can cause 1-2% reflow. For documents where pixel fidelity matters, export to PDF from ODT directly (see our Word to PDF guide — same logic applies).

Can I go back — DOCX to ODT?

Yes. LibreOffice opens .docx natively and File → Save As → ODT emits one. This round-trip is mostly clean but loses DOCX-specific features (comment replies, some custom XML parts). Round-tripping a document repeatedly between formats is how features quietly strip — convert once, stay in the target format.

Can I batch-convert a folder of ODTs?

Three options. (1) Drop the folder into our converter — server-side parallel conversion, download a ZIP. (2) Locally, LibreOffice CLI: libreoffice --headless --convert-to docx *.odt in a directory. (3) A LibreOffice Basic macro that iterates through a folder.

What about tracked changes?

LibreOffice Save As DOCX preserves them cleanly — author, timestamp, and content all survive. Word's ODT import preserves the changes but sometimes simplifies author attribution on older revisions. If tracked changes matter, use LibreOffice for the conversion.

My converted DOCX is bigger than the ODT — why?

DOCX's schema is more verbose than ODT's for some features — style inheritance, relationship files, and Word's numbering.xml add overhead. For a clean document it's maybe 10-20% larger; for heavy-style documents sometimes 50%. Normal. If the output is multiple-MB larger, something odd happened during conversion — embedded images may have rasterized unnecessarily.

Does your converter need a LibreOffice or Word license?

No. LibreOffice is LGPL-licensed; we run it headless on our servers and bill you nothing. We don't need a Microsoft license because we're not touching Word — we're using LibreOffice's native DOCX export path.

I'm heading to PDF anyway — should I convert to DOCX first?

Usually no. Go ODT → PDF directly — fewer translation layers, higher fidelity. ODT → DOCX → PDF doubles the reflow opportunities. Our DOCX to PDF also accepts .odt input on the same endpoint, so you can skip the intermediate step.

Ready?

Our document converter →. Drop an .odt, pick .docx (or .pdf, or .txt) as the output, download. Free, no sign-up, no watermark. If you need the DOCX as a PDF next, chain through our DOCX to PDF — same pipeline, one button. Coming from Word and need the reverse? PDF to Word is the complementary path. For broader format strategy, see our Word to PDF guide and our CloudConvert comparison.