How to Send Books to Your Kindle

You have books that didn't come from Amazon — maybe a Humble Bundle haul, free classics from Project Gutenberg, technical books from O'Reilly, or an entire Calibre library. You want them on your Kindle. DropKind sends them wirelessly in seconds. Upload the file, and it appears in your Kindle library alongside everything else.

Create your DropKind account

Connect your Kindle

A short guided setup: add DropKind as an approved sender in your Amazon account and enter your Kindle email. Takes about a minute.

Upload your book

Upload an EPUB, PDF, DOCX, or other supported file. DropKind sends it to your Kindle wirelessly — no cables, no USB transfer, no emailing yourself attachments.

Read on your Kindle

Your book appears in your Kindle library in under a minute. It sits alongside your Amazon purchases and works with all the usual Kindle features — bookmarks, highlights, font adjustments.

Where people get ebooks outside Amazon

More books exist outside the Kindle Store than most people realize. Humble Bundle runs regular book sales — pay what you want for bundles of sci-fi, fantasy, comics, RPG sourcebooks, and technical titles. Project Gutenberg has over 70,000 free public domain classics. O'Reilly offers DRM-free technical books. StoryBundle, Smashwords, and many indie publishers sell directly in EPUB and PDF. If you use Calibre to manage your library, you probably have hundreds of books already sitting on your hard drive. All of these can go straight to your Kindle.

EPUB vs PDF for books

For ebooks, EPUB is almost always the right choice. Text reflows to fit your screen, you can adjust font size, and chapters work like a real book. Kindle has supported EPUB natively since 2022 — no conversion needed. PDF books are a different story. The text is locked to fixed page dimensions, which means tiny text and constant zooming on smaller Kindles. If your book is only available as PDF, DropKind can convert it to EPUB with reflowable text. The conversion takes a few minutes for short books and up to 30 minutes for longer ones, but the reading experience is dramatically better. One exception: heavily illustrated books, comics, and textbooks with complex layouts are usually better left as PDFs.

Managing a personal Kindle library

Once you start sideloading books, you'll want a system. Most people keep their master library in Calibre on their computer and send individual books to their Kindle when they're ready to read. DropKind makes the sending part effortless — upload the file and it's on your device. A few things to know: EPUB is the best format (Kindle accepts it natively), MOBI is dead (Amazon stopped accepting it in 2023), and DRM-protected books from other stores like Kobo or Google Play won't work. Stick with DRM-free sources and EPUB files, and everything just works.

Frequently Asked Questions

What file formats can I send?

DropKind accepts EPUB, PDF, DOCX, DOC, TXT, RTF, HTML, and images. EPUB is the best format for books — it reflows to fit your screen and supports chapters, fonts, and images. MOBI is not accepted (Amazon stopped supporting it in 2023).

What about DRM-protected ebooks?

DRM-protected books from other stores (Kobo, Google Play Books, Barnes & Noble) cannot be sent to Kindle. Only DRM-free files work. Most indie publishers, Humble Bundle, Project Gutenberg, and O'Reilly sell DRM-free.

What's the file size limit?

15 MB per file. Most ebooks are well under this — a typical EPUB novel is 1-3 MB. Large illustrated books or comics may exceed the limit.

Should I send my book as EPUB or PDF?

EPUB whenever possible. It gives you reflowable text, adjustable fonts, and proper chapter navigation. If you only have a PDF, DropKind can convert it to EPUB for a better reading experience. Keep the PDF as-is only for heavily illustrated or fixed-layout content.

Ready to try it?

Send your first document to Kindle in under a minute.

Free to use. No credit card required.