Free · Private · In your browser
EPUB to MOBI Converter
For older Kindles that still need MOBI. Converted in your browser, never uploaded.
Files never uploaded Works offline Free, no signup No file size limits
How it works
- Drop your EPUB into the box above.
- The text, chapters, images and metadata are repacked into a classic Mobipocket container.
- Copy the .mobi to your Kindle over USB and it appears in your library.
Why “no upload” matters
Every conventional converter site works the same way: your file travels to their server, sits in their queue, gets converted on their hardware, and – you hope – gets deleted afterwards. You can’t verify any of it. The FBI has even warned about free converter sites that use that upload as a way to deliver malware or harvest the documents themselves. Your books are yours; a format change shouldn’t require handing them to a stranger.
ebook.tools removes the question entirely. The converter is delivered to your browser as code and runs on your machine; the file you drop is opened from memory, transformed, and saved back – the network isn’t involved at all. That isn’t a policy promise, it’s an architecture, and you can test it: load this page, switch off your wifi, and convert. It works exactly the same, because there was never anything to send.
Do you actually need MOBI? An honest answer first
Kindle from 2012 or later? You probably don't want MOBI. Modern Kindles read EPUB via Send to Kindle – run your book through the Kindle EPUB fixer and send it directly for a better result. MOBI is for genuinely old hardware.
Every other converter site still pretends MOBI is the current Kindle format. It isn't – Amazon retired it years ago, and pushing a 2005-era container at a 2020s Kindle throws away typography and features for nothing. What MOBI is still good for is the first decade of Kindle hardware: the original 2007 model, the DX, the early keyboards and entry-level models before the Paperwhite era. Those devices never learned another sideload format, millions still work perfectly, and if you own one, MOBI is simply how books get onto it.
The conversion takes your EPUB apart and rebuilds it the way old Mobipocket tooling did: chapters concatenated with page-break markers, an in-book table of contents wired up with the byte-offset links MOBI navigation uses, images embedded as records inside the container, and title, author and description written into the header so your Kindle's library shows the book properly. Text is compressed with PalmDoc – the same scheme the originals used – so files stay small enough for devices with megabytes, not gigabytes, of storage.
Be realistic about fidelity: classic MOBI predates real CSS, so decorative styling flattens to the basics – headings, emphasis, paragraphs, images, lists. On an e-ink screen from 2009 that's exactly what you want anyway. As always: DRM-protected EPUBs are detected and declined, this runs entirely in your browser, and your book never touches a server.