Guides
Guides for scanned and old books
Each guide is built on a conversion we ran ourselves. The numbers come from the files, and you can download the files.
Public-domain books
Internet Archive and Google Books PDFs to EPUB: why the free EPUB falls short, and what to do
We measured the Internet Archive's own EPUB of an 1872 scan: empty contents, running heads in the text, EPUBCheck errors. Here is a cleaner way.
Kindle
Can Kindle read PDF? Yes, but not scanned ones. Here is the fix
Kindle shows PDFs as fixed pages, and a scanned PDF has no text to convert. How to make it readable, with a measured 214-page example.
Tool comparison
Calibre, OCRmyPDF or k2pdfopt for a scanned book? We ran the same scan through each
One 214-page scan through Calibre, OCRmyPDF + Calibre and upub, plus k2pdfopt's documented output. Words recovered, contents and EPUBCheck.