Which PDFs reflow well into an e-book
A PDF fixes every line to a page the size of paper, so on a six-inch e-reader it is either tiny or needs constant panning. An EPUB lets the reader choose the size, and the text flows to fit the screen. Converting works well for some PDFs and poorly for others, and the difference is visible before you start.
Updated
Which tool you need
A novel, a report or a long article in one column
These convert best: the paragraphs flow cleanly, and the headings become the chapters an e-reader lists in its contents.
A paper or magazine laid out in two columns
Expect some passages out of order. Check the pages the result names; where they matter, the original PDF may be easier to read on a larger screen.
A scanned book
There is no text to reflow, only pictures of pages. It would need text recognition first, which PDFCheetah does not offer.
An EPUB that has to become a PDF again
EPUB to PDF sets a book back onto fixed pages for printing.
What reflowing lets go of
Everything that belongs to the page rather than to the text is dropped: the running title at the top, the number at the bottom, the hyphen that split a word at the end of a line. What is left is the text in reading order, divided at its headings.
A heading is recognized by its size, so a PDF whose headings are the same size as the body, set only in bold for instance, has no headings to divide at. The book is then cut into chapters of twenty pages each, named by the pages they cover. The words are all there; only the contents list says less.
How the chapters are chosen
The chapter level is the largest heading size the document uses at least twice, so a title set once in very large type does not become the only break in the book. Smaller headings stay inside their chapter as sub-headings, and bulleted or numbered lines stay lists.
Before you download, the result lists every chapter with the page it starts on. The e-reader's contents list will show exactly those divisions, so that list is the place to catch a chapter break in the wrong spot.
What the e-reader sees
The book is EPUB 3, with an older-style table of contents included beside the new one, so readers made before EPUB 3 still show the chapter list. The title and author you type are what the library shows; with no title, the PDF's file name is used.
The book is marked as written in English, whatever language the PDF is in. Its stylesheet asks only for a plain serif face and sizes relative to the reader's own, so the e-reader's font and size settings take over.
What to know before you start
- Pictures, tables, fonts and colors stay behind in the PDF.
- Columns set side by side can interleave.
- A password-protected PDF needs unlocking before its text can be read.
- The PDF's own bookmarks are not used: chapters come from the size of its headings.