Convert EPUB to MOBI
FileReshape's EPUB to MOBI converter turns a DRM-free EPUB into a MOBI (Mobipocket) e-book that every Kindle e-reader opens when you copy it over USB, with chapters, headings, bold and italic text, links, pictures, the cover and a contents page. Fonts, colours and most layout are dropped, because MOBI cannot hold them. The book is converted in your browser and is not uploaded.
Did a file not convert correctly? E-mail [email protected], ideally with a small sample file, and it will be fixed.
Key facts
- Input: EPUB (.epub). Output: MOBI (.mobi).
- Your files are not uploaded: the work is done in your browser, on your own device.
- File size: up to 300 MB per book.
- Needs a current browser (Chrome, Edge, Firefox or Safari) on a computer, tablet or phone; nothing to install.
- Free to use, with no sign-up.
Why convert EPUB to MOBI
Kindle e-readers do not open EPUB files that you copy to them with a USB cable: books copied over USB must be MOBI or AZW3. MOBI is the older of the two and the one every Kindle reads, from the first models and the Kindle Keyboard to the current Paperwhite. This tool reads the EPUB in your browser, follows its reading order, and writes each chapter as Mobipocket markup: headings, paragraphs, bold, italic, underlined and struck-through text, lists, simple tables, centred and right-aligned text from the book's styles, and a page break between chapters. Links inside the book keep working, the table of contents becomes a contents page with links at the start of the book, and the title, authors, language, publisher, description and cover go into the file, so the Kindle shows them in its library. Pictures are stored as JPEG or GIF of at most 127 KB each, the limit older Kindles and KindleGen used; larger pictures, PNG, WebP and SVG are converted and made smaller when needed. If you send books with Send to Kindle (e-mail, app or web page), you do not need this tool: since 2022 Send to Kindle accepts EPUB files and no longer accepts MOBI.
How to convert EPUB to MOBI
- Drop your .epub file in the box, or click to choose it. The title, author, language and number of parts appear.
- Click Convert to MOBI and save the .mobi file.
- Connect the Kindle to your computer with a USB cable and copy the file into the Kindle's documents folder.
What changes when you convert
Send to Kindle no longer accepts MOBI
Amazon's Send to Kindle service (the e-mail address, the app and the web page) takes EPUB files since 2022 and has stopped accepting MOBI. If that is how you get books onto your Kindle, send the EPUB itself. MOBI is for copying over USB, for older Kindles and for other programs that only read MOBI.
MOBI shows only simple formatting
MOBI is a format from before CSS. Headings, paragraphs, bold, italic, alignment, lists, tables and pictures come through; embedded fonts, colours, font sizes, margins, floating pictures, audio, video and scripts do not. Fixed-layout EPUBs such as comics and picture books are converted as flowing text with pictures, which may not look like the original. For a richer Kindle file, Calibre on a computer can write AZW3.
Books with DRM cannot be converted
EPUBs bought in many shops are protected with DRM (Adobe ADEPT, Apple FairPlay or similar), which encrypts the chapters. The tool reads the book's encryption list and tells you instead of writing an unreadable file. DRM-free books, such as those from Project Gutenberg, Standard Ebooks and many small publishers, convert fine.
About the formats
EPUB
EPUB is the open standard for e-books, first published by the IDPF in 2007 and maintained by the W3C since 2017. Apple Books, Kobo, Google Play Books and most library and e-reader apps open it. The text reflows to fit the screen and the reader's chosen font size, so an EPUB has no fixed pages.
- An EPUB is a ZIP archive of XHTML pages, CSS, images and fonts, plus a package file (.opf) that lists them.
- The spine in the package file sets the reading order. EPUB 2 (2007) and EPUB 3 (2011 onwards) are both common.
- Books with DRM, such as Adobe ADEPT or Apple FairPlay, are encrypted and only open in the apps that hold the key. Kindle books use Amazon's own formats, not EPUB.
- Fixed-layout EPUBs, used for comics and picture books, have set pages instead of reflowing text.
MOBI
MOBI is the Mobipocket e-book format, which Amazon bought in 2005 and used for the first Kindle devices. A MOBI file holds simple HTML with images, compressed in a Palm database container. Amazon has since replaced it with KF8 (AZW3) and KFX, and Send to Kindle no longer accepts MOBI files, but many older books and downloads still come as .mobi.
- Old Kindle books bought from Amazon use the .azw extension; they are MOBI files, usually with DRM.
- MOBI supports only basic formatting: no embedded fonts, little CSS and no fixed-layout pages.
- Many .mobi files made by KindleGen also contain a KF8 (AZW3) version of the same book.
- Text is compressed with PalmDOC (LZ77) or Huffman coding and split into 4 KB records.
Frequently asked questions
Is my book uploaded?
No. The EPUB is unpacked and the MOBI file is written by your browser on your own device. Nothing is sent to a server.
How do I put the MOBI file on my Kindle?
Connect the Kindle with a USB cable. It shows up as a drive named Kindle on Windows and macOS (newer Kindles with USB-C may need Amazon's file-transfer app on a Mac). Copy the .mobi file into the documents folder, eject the Kindle, and the book appears in the library.
Will the table of contents work?
The book gets a contents page at the start with a link to each chapter from the EPUB's table of contents. Links between chapters and to footnotes keep working.
Why are some pictures smaller than in the EPUB?
MOBI books for Kindle keep each picture as a JPEG or GIF of at most 127 KB. Pictures that are larger, or stored as PNG, WebP or SVG, are converted to JPEG (with a white background behind transparent parts) and made smaller until they fit.