Free online ODT to EPUB converter

An EPUB file is required when an ODT document must be read in an ebook app, on an e-reader, or submitted to a platform that does not accept OpenDocument files. The conversion changes fixed office pages into reflowable content that can adapt to screen size and reader-selected font settings.

What the ODT format is

ODT (OpenDocument Text) is an editable word-processing format used by LibreOffice Writer, Apache OpenOffice Writer, and other office suites. Microsoft Word can open and save ODT files, but complex formatting may not remain identical.

An ODT file is a ZIP-based package containing XML document content and resources such as styles, images, tables, footnotes, metadata, and page settings. It is common for documents created with free office software, exchanged using open standards, or retained without depending on a proprietary word-processing format.

What the EPUB format is

EPUB is a ZIP-based ebook container built from XHTML, CSS, images, fonts, navigation data, and package metadata. EPUB 3, including the current EPUB 3.3 specification, supports text, images, links, footnotes, tables of contents, cover images, and embedded fonts.

A reflowable EPUB adapts paragraphs to the reader’s screen, orientation, and font size. It suits novels, reports, manuals, and other mostly linear documents, but it is not designed to preserve exact office-page geometry. Documents with complex columns, forms, tightly positioned diagrams, or print-dependent layouts may require substantial editing; PDF is usually better when unchanged page appearance matters.

Convert with LibreOffice Writer

LibreOffice Writer is usually the best first choice because it can export the document directly and uses the source document’s paragraph styles.

1. Open the .odt file in LibreOffice Writer.
2. Apply built-in styles such as Heading 1, Heading 2, and Text Body instead of formatting headings only by changing font size. Heading styles provide the structure used for EPUB navigation and the table of contents.
3. Review images, hyperlinks, footnotes, lists, tables, special characters, and unwanted manual page breaks. Give images appropriate alternative text when the source document supports it.
4. Choose File → Export As → Export as EPUB.
5. Choose EPUB 3 when the target application supports it. Use a reflowable layout for ordinary text; choose fixed layout only when preserving positioned elements is more important than adapting to different screens.
6. Enter the title, author, language, cover image, and table-of-contents depth in the export dialog, then save the result as a file such as book.epub.
7. Open the EPUB in a reader and check chapter navigation, images, links, footnotes, symbols, tables, and page transitions.

Use Pandoc for repeatable conversions

Pandoc is suitable for scripted or batch conversion when the ODT contains straightforward, structurally styled text. A basic command is:

pandoc input.odt -o output.epub --toc --metadata title="Book title" --metadata author="Author name"

CSS and a cover image can be added with:

pandoc input.odt -o output.epub --toc --css=style.css --epub-cover-image=cover.jpg

Quote paths containing spaces or shell-special characters. Pandoc may not reproduce complex Writer layouts, floating objects, or page-oriented formatting exactly, so inspect the generated file rather than treating a successful command as a quality check.

Use Calibre as a desktop alternative

Calibre can convert ODT files and is useful for batch jobs or additional EPUB metadata editing. Add the file with Add books, select it, choose Convert books, set the output format to EPUB, adjust metadata or table-of-contents settings, and select OK. Use Save to disk after conversion to copy the EPUB out of the Calibre library.

Convert without installing software

You can convert the file for free on 101convert.com: upload the ODT file, select EPUB, start the conversion, and download the result. Do not upload confidential documents unless the service’s storage, processing, and deletion policies are acceptable.

Quality and compatibility checks

• Margins, headers, footers, columns, floating objects, and manual page breaks can change or disappear because EPUB uses screen-based flow rather than fixed office pages.
• Wide or complex tables may overflow on phones. Simplify them, split them, or provide a separate accessible representation.
• Resize images to the largest display size needed. JPEG is generally suitable for photographs; PNG is better for line art or transparency. Oversized images unnecessarily increase the EPUB size.
• Test the file in at least one desktop reader and one mobile or e-reader application. CSS support, embedded-font handling, fixed-layout support, and footnote behavior vary.
• Run an EPUB validator before submitting the file to a publisher or distribution platform. Preserve the original ODT and inspect the final EPUB, because LibreOffice, Pandoc, and Calibre can produce different results from the same source.