Convert ODT to DOCX

How it works

Both formats are the same kind of thing: a zip archive containing XML that describes paragraphs, styles, tables and the relationships between them. The conversion unpacks one description, maps it onto the other's vocabulary, and writes a new archive.

Because the underlying models are so similar, most objects have a direct counterpart. A heading is a paragraph with a named style in both. A table is rows of cells in both. Footnotes, comments and tracked revisions all exist in both, which is why they survive.

The gaps are in the corners — features one suite added that the other never had an equivalent for, and layout details described in units or reference frames that do not line up exactly.

Two standards, and why there are two

OpenDocument was published as an ISO standard in 2006, developed in the open by a consortium and adopted by governments that wanted their public records in a format not controlled by a single vendor.

OOXML — the format behind .docx — was standardized shortly afterwards, by a process widely criticised at the time, and became the default of the software almost everyone already had.

So the two exist for reasons that are mostly political, and the practical consequence is simple: one is technically excellent and the other is what is installed. Converting is how you stop caring which is which.

When to send PDF instead

If the recipient is going to read the document and not change it, neither of these is the right answer. PDF renders identically everywhere, cannot be edited by accident, and never raises the font question at all.

Convert to .docx specifically when you want the document back with changes in it. That is the case where the recipient needs a file their software will edit comfortably, and it is the only case where the format's inconveniences are worth accepting.

What travels well, and what to check

Both formats are zipped XML describing the same kinds of thing, so the conversion is a translation between two vocabularies rather than a rasterization. Most documents come through intact.

Body text, headings, bold and italic, lists, ordinary tables, images, page size and margins all map cleanly. So do footnotes, headers and footers. For a report, a letter or a set of meeting notes, the converted file is usually indistinguishable from one authored in Word.

The parts to look at are where the two formats model things differently. Complex nested tables — tables inside table cells — sometimes lose a border or a width. Text boxes and floating images can shift, because anchoring rules differ. Automatic numbering that restarts at a specific point occasionally renumbers from the top. Equations translate through a different model again and deserve a direct look.

Tracked changes and comments generally survive, and are worth verifying specifically if the document is going into a review cycle, because losing a revision history silently is worse than losing formatting.

The efficient check is to open both and compare the last page. Layout drift accumulates, so any difference in how content flows shows up most clearly at the end — a document that ends on the same page with the same content is a document that survived.

Fonts are the usual cause of drift

When a converted document looks close but not quite right, the reason is generally that it is being rendered with different type.

A .docx names the fonts it wants; it does not usually contain them. If the document was written with a font the recipient does not have, their software substitutes something else, and the replacement has different letter widths. Lines wrap differently, paragraphs grow or shrink by a line, and content moves.

This is invisible on the machine that created the file, because that machine has the fonts. It appears only on the recipient's screen, which is precisely where you cannot check it.

The reliable fix is to use fonts the destination will certainly have. Arial, Times New Roman, Calibri and Cambria are safe in Word; Liberation Sans and Liberation Serif are the metric-compatible equivalents that make LibreOffice documents behave in Word. Avoid anything decorative or newly installed unless you know the recipient has it.

Where the layout genuinely matters and the recipient only needs to read it, send a PDF. The fonts are embedded and the question does not arise.