How to convert MOBI, AZW3 or FB2 e-books to EPUB (and EPUB to MOBI)

How to convert MOBI to EPUB (and the other pairs) in the browser

Open the tool for your pair of formats (for example, MOBI → EPUB), upload the book and click "Convert and download." There is no destination picker: each conversion is its own tool, with a single button. The file comes out with the same name and the new extension, and everything happens in your browser. Books with DRM (the store lock) stop with a warning and are not converted.

1. Pick the tool for your case: MOBI → EPUB, AZW3 → EPUB, FB2 → EPUB, EPUB → MOBI or AZW3 → PDF.
2. Upload the book file, without DRM. You can upload several: the button changes to "Convert N books."
3. Click "Convert and download." The result is downloaded with the original name and the new extension (for example, my-book.epub).
4. Open the file in your reader and check the text, the images and the table of contents.

If your book is a Kindle AZW3 (or .azw), the path is the same in the matching tool: it turns the AZW3 into EPUB so you can read it on a Kobo, a phone, a tablet or the Kindle itself.

Why there are so many e-book formats

Each store and each e-reader adopted its own format. EPUB is the W3C open standard that almost every device reads: Kobo, phones, tablets and newer Kindles. MOBI and AZW3 are Kindle's older formats. FB2 (FictionBook) is common in book collections. And PDF is not really an e-book format: it has fixed pages, great for printing, but it does not adapt to small screens. Converting means moving the same book from one format to another so it opens where you want to read. For the opposite path, from a PDF to an e-book, see how to convert PDF to EPUB.

Important: unprotected books only (no DRM)

All of these converters work only with unprotected books. Many books bought from stores come with a lock called DRM, which prevents copying and converting. That lock is not removed here: it is a legal limitation. In the conversions from MOBI and AZW3, when it detects the protection, the tool stops and shows the warning that the book has Kindle store protection (DRM) and cannot be converted. Your own books, public-domain titles and books sold without DRM convert normally.

What comes out the other end (what is kept and what is not)

• MOBI and AZW3 → EPUB: the full text comes through in reading order, with the internal headings, the cover and the images. The EPUB is built as a single content file, with page breaks between sections; the per-chapter table of contents is not recreated, so the reader's chapter-to-chapter navigation does not work. Images from very old MOBI files (the original Mobipocket format) may not be recovered; in newer Kindle files (AZW3) they come through.
• FB2 → EPUB: sections, headings, paragraphs, emphasis (bold and italic) and images are kept; more complex FB2 styles and CSS (styling code) are not interpreted. The book also comes out as a single block, with no per-chapter table of contents.
• EPUB → MOBI: text and images are preserved; advanced formatting is simplified, with no complex styles.
• AZW3 → PDF: the look of the pages is preserved, but the text becomes an image, so you cannot select, search or copy it.
• Everything runs in the browser; the original file stays untouched on your computer.
• If the file is damaged, you see "Could not read this book. It may be protected or damaged."; if there is no text inside, "We found no readable content in this book."

FB2 to EPUB

Got a FictionBook and want to bring it to a Kobo, a phone or a Kindle? The FB2 to EPUB conversion keeps the book's structure, the text emphasis and the embedded images.

EPUB to MOBI: only for old Kindles

MOBI is an old format. Modern Kindles already read EPUB directly through the Send to Kindle feature, so in most cases you no longer need it. Use the EPUB to MOBI conversion only if the device is old and does not accept EPUB. Keep in mind that advanced formatting is simplified: text and images stay, elaborate styles do not.

AZW3 to PDF: fixed pages, text as image

Want fixed pages to print or read in a PDF reader? The AZW3 to PDF conversion accepts .azw3, .azw and .mobi and builds A4 pages with the book's look. The catch: each page comes out as an image, so the text is not selectable or searchable, and the file is larger. Fine for printing; to highlight and copy passages, prefer EPUB. Starting from an EPUB, the conversion to PDF keeps the text searchable: see how to convert EPUB to PDF. And to edit the book in an ordinary editor, how to convert EPUB to Word, Markdown or HTML.

Which format to choose

• To read on almost any device, convert to EPUB: the safest, most universal choice.
• For a very old Kindle that does not read EPUB, MOBI still helps.
• For printing, PDF; remember the text goes as an image.
• If the book has DRM, no conversion will work; the way to go is reading it in the app of the store where it was bought.

Everything happens in your browser: the e-book is converted on your own device and is never sent to any server.