Convert EPUB to MOBI

Convert EPUB files to MOBI right in your browser, one file or a whole batch at a time. Free, private and fast: everything runs in your browser, nothing is uploaded, and there is nothing to install.

Convert EPUB files to MOBI right in your browser, one file or a whole batch at a time. Drop your files into the box above, adjust the options if you want, and download the result. The FansBond EPUB to MOBI tool works entirely in your browser, so your files never leave your device. It is free, needs no account, and there is nothing to install.

Private by design: files are processed on your device and are never uploaded to a server.
Nothing to install: it works in Chrome, Safari, Firefox and Edge on desktop, Android and iPhone.
Free with no sign-up, no watermark and no daily limits.
Accepts: EPUB.
Saves as: MOBI.

What EPUB to MOBI does

Ebook conversion changes how a book is packaged for a reading app or device. EPUB to MOBI reads the chapters, headings, paragraphs, lists, tables and images of the source file (from a PDF, only the text) and writes them into a new format.

EPUB output is an EPUB 3 book with a table of contents built from the headings. MOBI output uses the older Mobipocket format that Kindle devices can open. PDF output lays the text out on fixed pages with embedded fonts. The original styles and fonts of the book are not copied.

How to use EPUB to MOBI

Drop your EPUB files into the box, or click to choose them.
Pick the output format and any options.
Click Convert. The conversion runs on your device.
Download each file, or all of them at once as a ZIP.

When to use EPUB to MOBI

Convert a DRM-free EPUB from an independent store to MOBI for an older Kindle that cannot open EPUB.
Turn a PDF manual or report into EPUB so the text reflows and stays readable on a small phone or e-reader screen.
Make a printable PDF from an EPUB to read on a laptop or print a few chapters on paper.
Save a long web article as an HTML file, then convert it to EPUB to read it offline on an e-reader.

Settings explained

Output format: Chooses the type of book to create. EPUB works with Apple Books, Google Play Books, Kobo and most e-readers. MOBI is for older Kindle devices. PDF keeps fixed pages, and TXT keeps only the text.
Page size: Shown when saving as PDF. A5 is close to a paperback page and comfortable on tablets. A4 and Letter suit printing on standard office paper.
Orientation: Shown when saving as PDF. Portrait is the normal choice for books. Landscape gives long lines, which are harder to read, but it can help with wide tables.
Document title (optional): Sets the book title that reading apps show in the library. Leave it empty to keep the title stored in the source file, or else the file name.

What changes when you convert EPUB to MOBI

The text, headings, lists, tables and images are carried over. Fonts, exact line breaks and page layout are rebuilt for MOBI, so check the result before you send it.

Format comparison

Format	Full name	Type	Compression	File extension	Developed by	Released
EPUB	Electronic Publication	ebook	—	.epub	IDPF	2007
MOBI	Mobipocket eBook	ebook	—	.mobi, .prc	Mobipocket	2000

What is EPUB?

EPUB (Electronic Publication) is an ebook format introduced by IDPF in 2007. Files use the .epub extension.

EPUB is an open e-book standard first published by the International Digital Publishing Forum and now maintained by the W3C. An EPUB file is a ZIP archive with XHTML content, CSS styles, images and metadata. The text is usually reflowable, so it adapts to the screen size and the reader's font settings.

EPUB is the right choice for books, long articles and documents that people will read on e-readers, tablets and phones, where reflowable text and adjustable font sizes are more comfortable than fixed PDF pages.

Complex layouts, such as magazines or comics, do not always display well. Many purchased EPUB books use digital rights management, which prevents conversion. Reading apps differ in how well they support EPUB 3 features.

Apple Books, Google Play Books, Kobo devices and Calibre open EPUB files. Kindle devices and apps accept EPUB through Send to Kindle, which converts the file. On Windows and Android, a separate reading app is usually needed.

What is MOBI?

MOBI (Mobipocket eBook) is an ebook format introduced by Mobipocket in 2000. Files use the .mobi or .prc extension.

MOBI is the Mobipocket e-book format, based on the older PalmDOC format. Amazon bought Mobipocket in 2005 and used MOBI as the basis of early Kindle formats such as AZW. It stores simple HTML-based content with limited styling compared with EPUB or later Kindle formats.

MOBI is now useful mainly for older Kindle e-readers and for opening existing e-book collections. For new e-books, EPUB is the better choice, and current Kindle devices receive books in newer Amazon formats.

MOBI is deprecated. Amazon no longer accepts MOBI files through Send to Kindle or for new Kindle publishing, and the format supports only basic formatting. Purchased books may use digital rights management that prevents conversion.

Older Kindle devices and the Calibre e-book manager open MOBI files. Some third-party reading apps on Android, iOS, Windows and macOS also read them. Web browsers, Apple Books and Google Play Books do not support MOBI.

Why use FansBond EPUB to MOBI

Most online converters upload your files to their servers. FansBond EPUB to MOBI does the work inside your browser instead, using WebAssembly and modern browser APIs. Your files stay on your device, which is safer for private photos, contracts and unreleased work, and it is often faster because nothing has to upload or download.

There are no queues, no watermarks and no account. Once the page has loaded, the tool keeps working even on a slow connection.

Tips for the best result

Use the title field when the source has an unclear title, such as a file name like scan_0042. E-readers sort and search the library by this title.
From a PDF, each page usually starts a new section in the table of contents, and paragraphs that cross a page break are split in two.
Scanned PDFs contain no text. They are converted as page images, which do not reflow on a small screen, so EPUB gives little benefit.
Check the table of contents after converting. Chapters are split at the main headings, so a book without real headings gets long or numbered sections.

How EPUB to MOBI works in your browser

Documents are first read into a common structure of headings, paragraphs, lists, tables and images. DOCX files are read with mammoth, PDFs with pdf.js text extraction, and EPUB files are unpacked in the browser.

The structure is then written in the target format: DOCX with the docx library, PDF with pdf-lib and embedded Unicode fonts, EPUB and MOBI as standard ebook packages. The content is kept, but the exact page layout of the original is rebuilt rather than copied.

Privacy and security

Most online converters upload your files to a server, process them there and keep a copy for some time. EPUB to MOBI works differently: the code is downloaded to your browser once, and your files are read and written only on your device.

You can check this yourself: after the page has loaded, turn off your internet connection and the tool still works. This makes it safe for contracts, IDs, medical records, private photos and unreleased work.

Frequently asked questions

Is EPUB to MOBI free?

Yes. EPUB to MOBI on FansBond is completely free, with no sign-up, no watermark and no daily limit.

Are my files uploaded to a server?

No. Your files are processed in your browser on your own device. They are never sent to FansBond or anyone else.

Do I need to install any software?

No. It works in any modern browser (Chrome, Safari, Firefox, Edge) on Windows, Mac, Linux, Android and iPhone.

Is there a file size limit?

There is no fixed limit. Because the work happens on your device, the practical limit depends on your device's memory. Most phones handle files of a few hundred megabytes, and computers handle much more.

Can it convert ebooks with DRM?

No. Books protected with DRM, such as most purchases from the Kindle, Apple Books or Kobo stores, are encrypted and cannot be read by this tool. It works with DRM-free files, for example from publishers that sell without DRM, from Project Gutenberg, or your own documents.

Which MOBI files can it open?

It opens MOBI files without DRM that use PalmDOC compression or no compression, which covers most MOBI ebooks. Files with the rare HUFF/CDIC compression cannot be opened, and newer Kindle formats such as AZW3 and KFX are not accepted. Convert those with desktop software first.

Will the MOBI file work on my Kindle?

The file uses the classic Mobipocket format, which Kindle e-readers open when you copy it over USB into the documents folder. Images are stored as JPEG. Amazon's Send to Kindle service no longer accepts MOBI files, so send the EPUB version there instead.

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