DOCX to MOBI Converter

Convert DOCX to MOBI Online

Turn a Microsoft Word document into a reflowable MOBI ebook that flows to fit any Kindle screen, with chapter breaks and a navigable table of contents instead of fixed Letter-size pages. Worth knowing up front: MOBI is Amazon's legacy format, and Send to Kindle stopped accepting MOBI files on December 20, 2023 — so MOBI now works mainly by USB sideload or in apps like Calibre. If your goal is to wirelessly push a new book to a current Kindle, convert DOCX to EPUB instead; MOBI is the right choice when you specifically need the older format for an existing library, an older reader, or a device that never adopted EPUB.

How to Convert DOCX to MOBI

1. Upload Your DOCX File: Drag and drop your .docx into the box or click "+ Add Files" to pick it from your computer, Google Drive, or Dropbox.
2. Confirm MOBI as the Output: The target format is already set to MOBI. The converter maps your Word headings, paragraph styles, and embedded images into the ebook's reflowable structure automatically, so the defaults are tuned for clean output.
3. Tidy the Source for Best Results: For a cleaner ebook, base your chapters on Word's built-in Heading 1/Heading 2 styles before uploading — these become the navigation entries inside the MOBI.
4. Convert and Download: Click "Convert" and download your .mobi. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared or made public.

MOBI vs EPUB for Kindle

Frequently Asked Questions

Can I still send a MOBI file to my Kindle?

Not wirelessly through Amazon's Send to Kindle service — Amazon wound that down starting November 1, 2023 and fully stopped accepting MOBI (and the related AZW and PRC formats) on December 20, 2023. You can still copy a MOBI onto a Kindle over USB, and MOBI files already in your library keep working. For wireless delivery of a new title, convert to EPUB instead.

Should I use MOBI or EPUB for a new ebook?

For anything new aimed at a current Kindle, EPUB is the better target: Amazon recommends it, Send to Kindle accepts it, and it is an actively maintained open standard. MOBI makes sense when you specifically need the older format — for an older e-reader, an existing MOBI collection, or a tool that expects it. You can convert DOCX to EPUB in one step here.

Will my Word formatting carry over to the MOBI?

Headings, paragraph styles, bold and italic, lists, and embedded images carry across, and Word headings become the ebook's navigation. MOBI is reflowable, so fixed page layout, precise column positioning, headers/footers, and footnotes anchored to a printed page do not translate the way they would in a PDF — the text reflows to fit each screen. In our testing, a 40-page Word manuscript built from Heading 1/Heading 2 styles produced a MOBI with a clean, tappable chapter list.

How do I get a working table of contents in the MOBI?

Structure the document with Word's built-in Heading 1 and Heading 2 styles rather than manually enlarged or bold text. The converter reads those heading levels to build the ebook's logical table of contents, which is what Kindle uses for chapter navigation. Plain text sized to look like a heading is treated as a normal paragraph and will not appear in the navigation.

Is there a file size limit for the Word document?

There is no fixed page or word-count cap; the practical limit is how large the upload is and how fast your connection can send it. Most manuscripts are a few megabytes even with images, so they convert quickly. If you also need to email the finished ebook, note that Gmail caps attachments at 25 MB — large illustrated files can exceed that and are better shared by link or copied over USB.