Common tools
Wallpaper, manga margin cropping, and format conversion tools.
Serial lookup
Enter a Kindle serial number to check model, factory info, and jailbreak support.
Send to Kindle
Send e-books to your Kindle via e-mail or the web; auto-converted and added to your library.
FAQ
Quick answers to common push, jailbreak, firmware, and format questions.
How do I send e-books to my Kindle?
Use the “Send entry”, upload the file, and pick a receiving device; you can also use Amazon’s official “Send to Kindle” e-mail.
Why did sending fail?
Common causes: unsupported format, receiving address not whitelisted, special characters in the filename, or files over 50 MB.
Does jailbreaking affect warranty?
Jailbreaking is a system-level modification and is not covered by official warranty terms.
Which e-book formats are supported?
Kindle natively supports AZW3, MOBI, TXT, PDF, and EPUB (newer firmware).
Can KOReader co-exist with the stock system?
Yes — KOReader lives on the user partition and stays out of the way of the stock reader.