ODT File Format (.odt)

An ODT file is a ZIP of XML parts specified by the OASIS OpenDocument standard (ISO/IEC 26300), the format LibreOffice Writer and OpenOffice Writer save by default instead of a Microsoft format.

.odtDocuments

ODT at a glance#

Full name	OpenDocument Text
File extension	.odt
Category	Documents
Developer	OASIS
First released	2005
MIME types	application/vnd.oasis.opendocument.text
Compression	Lossless
Specification	ISO/IEC 26300 / OASIS Open Document Format for Office Applications (ODF) v1.3
FileFlip support	FileFlip reads and writes this format

What a .odt file can hold#

These are the things a ODT file either supports or does not, and they are what decides whether a conversion keeps everything or quietly drops something.

Embedded metadata	Yes
Multiple images or pages	Yes
Selectable text	Yes
Encryption	Yes
Human readable	No
Comments	Yes
Schema or validation	Yes

Strengths and limitations of ODT#

What ODT does well

An open, ISO-standardized format not controlled by a single vendor, which is why several governments mandate it for official documents
LibreOffice and OpenOffice write it natively, so nothing is lost round-tripping within that ecosystem
A ZIP of readable XML parts, so a file can be inspected or repaired without specialized tools
Microsoft Word has read and written ODT natively since Office 2007 SP2

Where ODT falls short

Documents built in Word and saved as ODT sometimes shift spacing and fonts slightly, since the two formats' XML schemas don't map every feature one to one
Far fewer people recognize the .odt extension than .docx, which draws confused reactions when it's emailed to someone outside government or open-source circles
Some enterprise upload forms are hard-coded to expect DOCX specifically and reject an ODT file outright

Use ODT when the destination is LibreOffice, OpenOffice, or an organization whose policy specifically requires the open ODF standard.

Convert ODT to DOCX when the document needs to go to someone who only has Microsoft Word, still the more widely recognized format outside government and open-source use.

How to open a .odt file#

A .odt file opens in the programs below, grouped by the platform you are on. If you would rather not install anything, FileFlip converts ODT into a format your machine already opens, and it does it in the browser tab rather than on a server.

Platform	Programs that open it
Windows	LibreOffice Writer, Microsoft Word, WPS Office
macOS	LibreOffice Writer, Microsoft Word
Linux	LibreOffice Writer, OpenOffice Writer
Web	FileFlip, Google Docs

ODT questions people ask#

Can Microsoft Word open ODT files?

Yes, Microsoft Word has opened and saved ODT files natively since Office 2007 Service Pack 2, with no plugin required. Formatting generally survives well for standard text, tables and images, though some styles specific to one application can shift slightly on the round trip.

What's the difference between ODT and DOCX?

Both are ZIP archives of XML describing a word processing document, but they follow different, incompatible schemas: ODT implements the OASIS OpenDocument standard, and DOCX implements Microsoft's Office Open XML standard. They cover similar ground, text, styles, tables, images, but aren't interchangeable at the file level, which is why converting between them is a real translation rather than a rename.

Why do some governments require ODT instead of DOCX?

Because ODT is governed by an open, ISO-ratified standard that no single company controls, which agencies want for documents meant to stay readable for decades regardless of which vendor's software is popular later. The UK civil service and Germany's federal government are among those that have mandated ODF-family formats for official documents.

Does converting ODT to DOCX lose formatting?

Usually only in small ways. Standard text, tables, images and common styles convert cleanly between ODT and DOCX, but features that don't map directly between the OpenDocument and Office Open XML schemas, certain list numbering styles or advanced frame layouts, can shift slightly and are worth a quick check after converting.

Converting ODT files#

Every conversion runs inside your browser. The file is read from your disk, the work happens on your own machine, and nothing is uploaded. How FileFlip works names the engine behind each family and how to verify that for yourself.