What Is an ODT File?

How to open, edit, & convert ODT files

Screenshot of several ODT files in Windows 10
ODT Files.

A file with the .ODT file extension is an OpenDocument Text Document file. These files are most often created by the free OpenOffice Writer word processor program.

ODT files are similar to the popular DOCX file format used with Microsoft Word. They're both document file types that can hold things like text, images, objects, and styles, and are compatible with lots of programs.

If your file isn't a document, it might instead be an Origin Dialog Theme file used with the Origin data analysis and graphic software. These files are formatted in XML and used to change how various dialog windows in the program appear.

How to Open an ODT File

ODT file are built with OpenOffice Writer, so that same program is the best way to open one. However, LibreOffice Writer, AbiSource AbiWord (get a Windows version here), Doxillion, and several other free document editors can open ODT files, too.

Screenshot showing how to open an ODT file with OpenOffice Writer

Google Docs and Microsoft Word Online can open ODT files online, and you can edit them there as well.

Screenshot showing how to use Word Online to open an ODT file

Note: If you're using Google Docs to edit the ODT file, you have to first upload it to your Google Drive account through the New > File upload menu. ODT files opened with Microsoft Word Online are saved to OneDrive but you can initiate the upload from the Word Online page, unlike you can with Google Docs.

ODT Viewer is another free ODT viewer for Windows, but it's only useful for viewing ODT files; you can't edit the file with that program.

If you have Microsoft Word or Corel WordPerfect installed, those are two other ways to use ODT files; they're just not free to download. MS Word can both open and save to the ODT format.

Some of the programs just mentioned work on macOS and Linux, too, but NeoOffice (for Mac) and Calligra Suite (Linux) are some alternatives. Also remember that Google Docs and Word Online are two online ODT viewers and editors, meaning that they work on not only Windows but any other operating system that can run a web browser.

To open an ODT file on an Android device, you can install the OpenDocument Reader app. iPhone and other iOS users can use ODT files with OOReader or TOPDOX Documents, and probably some other document editors.

Origin Dialog Theme files are used by Origin, but you can't open the theme file in the program like you can other Origin file types like OPJU, OPJ, etc. Instead, an ODT file is stored in the program's "dialog" folder, usually in "C:\Program Files\OriginLab\Origin\Themes," from where Origin can read the settings and apply the appearance described by the theme file.

Note: If your ODT file is opening in a program that you don't want to use it with, see How to Change the Default Program for a Specific File Extension in Windows. For example, making that change would be helpful if you want to edit your ODT file in OpenOffice Writer but it's instead opening in MS Word.

How to Convert an ODT File

To convert an ODT file without having one of those ODT editors/viewers mentioned above, your best options are to use Zamzar or FileZigZag. Zamzar can save an ODT file to DOC, HTML, PNG, PS, and TXT, while FileZigZag supports some of those formats as well as PDF, RTF, STW, OTT, and others.

Screenshot showing the ODT conversion options on the FileZigZag website

However, if you already have MS Word, OpenOffice Writer, or any of those other ODT openers installed, you can just open the file there and then choose a different document format when you save it. Most of those programs support other formats in addition to the formats those online ODT converters support, like DOCX.

This is true for the online ODT editors as well. To convert the ODT file using Google Drive, for example, right-click it (from the list of files in your account) and select Open with > Google Docs. Then, use the Google Docs File > Download as menu to save the ODT file to DOCX, RTF, PDF, TXT, or EPUB.

Another option is to download a dedicated free document file converter.

Note: If you're looking for a method to save a DOCX file to ODT, using Microsoft Word is one easy way to do it. See What Is a DOCX File? for more information on converting DOCX files.

More Information on the ODT Format

The ODT format isn't the exact same as MS Word's DOCX format. You can see their differences explained on Microsoft's website.

ODT files are stored in a ZIP container but can also use XML, which makes it easier for the file to be created automatically without the need for an editor. Those types of files use the .FODT file extension.

You can make an FODT file from an ODT file with this command:

oowriter --convert-to fodt myfile.odt

That command is available via the free OpenOffice suite.

Still Can't Open the File?

If your file isn't opening with any of the several suggested programs above, there's a good chance that you don't really have an ODT file. Some file types share similar file extension letters that make it easy to confuse them with each other.

For example, an ADT file shares two of the three file extension letters but those files are not openable in an OpenOffice program. Instead, ADT files are ACT! Document Template files used with the Act! software.

Similarly, ODM files might look related to OpenOffice Writer but those are OverDrive Media files used within the context of the OverDrive app.

Some OpenDocument formats use a similar file extension but can't be opened with the same programs mentioned on this page. This includes ODS, ODP, ODG, and ODF files which, respectively, are used with OpenOffice's Calc, Impress, Draw, and Math programs. All of those programs can be downloaded through the main OpenOffice suite.