AZW3 to EPUB Converter turns an AZW3 Kindle ebook into an EPUB 3 file that opens in almost every reading app outside the Amazon world: Apple Books, Kobo, Google Play Books, PocketBook, Tolino, Calibre and Thorium. AZW3 is the KF8 Kindle format, and its text is stored as skeleton and fragment records that only Kindle software reassembles. The converter rebuilds those records into ordinary EPUB chapters, keeps the table of contents with its sub-entries, and turns fragment links such as footnote references and contents links into working EPUB links. The cover, the images, and the title, author, publisher, description, language, publication date and subjects move into the EPUB metadata. Drop in a DRM-free .azw3 file and the EPUB is ready a moment later, with no settings to choose. Older .azw, .mobi and .prc files work too. The book styling is simplified to a clean default layout that every reading app lets you adjust. Everything runs in your browser, so the book is never uploaded. Kindle store purchases are DRM protected and cannot be converted. After converting you can change the title, author or cover with EPUB Metadata Editor, check broken links and footnotes with EPUB Footnote & Link Doctor, or make a PDF with AZW3 to PDF Converter.
EPUB and AZW3 hold almost the same ingredients, which is why the conversion keeps so much. Both are built from XHTML chapters, CSS, images and a table of contents. The difference is packaging. An EPUB is a ZIP archive with one file per chapter, a manifest that lists every file, and a navigation document. An AZW3 file is a Palm database where the chapters have been taken apart: each chapter shell, called a skeleton, is stored separately from its content pieces, called fragments, and index tables record where each fragment must be inserted. Links between chapters are rewritten as fragment numbers and offsets, and image references become record numbers. Converting to EPUB means putting every chapter back together from its skeleton and fragments, renaming the files, turning fragment links back into anchors, extracting each image record into a real image file, and translating the EXTH metadata header into the EPUB package document. The navigation index becomes the EPUB table of contents, including nested entries for books divided into parts. Files that Calibre or Kindlegen saved as .mobi often contain both an old MOBI copy and a KF8 copy of the same book; the converter uses the KF8 copy because it preserves more of the original structure. KFX, the newest Kindle format, is a different container and is not supported.