Amazon Send-to-Kindle service accepts EPUB files, but is strict about validation and encoding. This tool fixes common issues that cause E999 and E21018 errors.
Use it now: https://deploy-preview-25--kindle-epub-fix.netlify.app/
- Encoding: Adds UTF-8 declaration if missing
- E21018 errors: Removes empty
alt=""attributes anddata-AmznRemovedattributes - Hyperlinks: Fixes NCX table of contents links to
<body>with ID hash - Language: Detects invalid/missing language tags, prompts for correction
- Stray images: Removes
<img>tags with no source - Unique identifier: Fixes mismatch between OPF package and dc:identifier
- NCX playOrder: Ensures sequential numbering
- Smart quotes: Normalizes unicode quotes/dashes in NCX navigation to ASCII
- EPUB3 attributes: Removes
epub:type,epub:prefix,xmlns:epub(not supported by older Kindle) - Bold/Italic tags: Converts
<b>,<strong>,<i>,<em>to CSS-styled<span>elements - Scripts: Removes
<script>tags - OPF metadata: Cleans up
primary-writing-modeand other problematic metadata
The book is processed entirely in your browser. Nothing is uploaded.
If your EPUB still fails after processing, use Kindle Previewer to open it. It shows detailed error codes (like E21018) that help identify remaining issues.
This tool comes with no warranty. Please keep your original EPUB. We do not guarantee the resulting file will be valid, but it should work with Send to Kindle.
Enhanced fork of innocenat/kindle-epub-fix