Guide
The complete guide to Send to Kindle
Getting your own books onto a Kindle is easy once you know which door to use. Here is every door, which files fit through each, and what to do when Amazon slams one in your face.
First: have the right file
Send to Kindle accepts EPUB, DOCX, PDF, TXT and a few image formats. It does not accept MOBI (dropped in 2022), AZW3, FB2 or comic archives. So step zero is usually a conversion: MOBI to EPUB, FB2 to EPUB, or DOCX to EPUB – the last worth doing even though DOCX is technically accepted, because a proper EPUB gives you chapters, a working table of contents and reliable formatting instead of Amazon's guesswork. Not sure which format you're actually holding? The formats guide sorts EPUB, MOBI, AZW3 and friends out in five minutes.
Method 1: the email address every Kindle owns
Every Kindle has a private address like yourname_123@kindle.com – find it under Manage Your Content and Devices → Preferences → Personal Document Settings. Two catches live there too: the sending address must be on your approved list, and attachments cap at 50MB per email. Attach the EPUB, send, and it appears on the device within minutes. Email is the method that works from anyone's machine with nothing installed.
Method 2: the Send to Kindle apps and website
Amazon's desktop apps (Windows/Mac), mobile share sheets, and the sendtokindle web uploader all push files up to 200MB straight to your library, no email hop involved. The browser version is the most convenient for occasional use: drag the file in, pick the device, done. This is the route with the size ceiling you're most likely to hit with image-heavy books – see the fix below.
Method 3: USB, the old reliable
Plug the Kindle in, and it mounts as a drive; drop compatible files into its documents folder. Modern Kindles read sideloaded EPUB fine. USB is instant, works fully offline, and skips every size cap – but the book won't sync position or appear in your Amazon library, and on recent Kindles (USB-C models) you may need to approve the connection on-screen first.
When Kindle says no
Rejections cluster around four causes, and none of them are mysterious:
- Too big: over 200MB, almost always oversized images. Full walkthrough here.
- Broken metadata: a missing language declaration is the classic silent killer.
- Malformed EPUB: a package file that doesn't validate.
- DRM: books locked by another store won't convert or send, by design.
The first three are exactly what the Kindle EPUB fixer was built for: drop the rejected file, read the diagnosis, click fix. It compresses images to Kindle's actual screen resolution, repairs the metadata Amazon checks, and repackages the file correctly – without touching a word of your text, and without the book leaving your device.
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The cheat sheet
- One-off book, any computer → email to @kindle.com (50MB cap)
- Regular sideloading → Send to Kindle app or web (200MB cap)
- Huge files, no internet, no Amazon account trail → USB
- File rejected → diagnose and fix it, then resend
Frequently asked questions
How do I send something to my Kindle?
@kindle.com address from any device (50MB cap), use Amazon’s Send to Kindle app or web uploader for drag-and-drop up to 200MB, or plug in over USB for no size limit at all. All three want a clean EPUB – convert first if your file is MOBI, AZW3 or FB2.