PDFreflow / Guides
How to convert a two-column PDF to EPUB
An EPUB has no pages and no columns: the text is one stream that wraps to the screen. To make one from a two-column PDF, the converter has to work out the order the columns are read in, and that is where most conversions go wrong.
Converting with Calibre
Calibre is free and the usual tool for this.
- Add the PDF to the library.
- Select it and choose Convert books.
- Set the output format to EPUB and convert.
- Open the EPUB and read a page from the middle, not the first one.
What goes wrong
PDF is one of the hardest formats to convert from: it records where each line sits on the page, not which line comes next. On a two-column page that shows up as:
- Columns read straight across: a line of the left column, then a line of the right, so no sentence survives.
- Page headers, footers and page numbers in the middle of a sentence, once per page.
- Words split at line ends, the hyphen left in (“re- view”).
- Formulas turned into strings of symbols, and figures pulled away from the text that refers to them.
A one-column PDF, such as a novel, usually converts well. Papers and textbooks are where it breaks.
What helps, and what doesn't
- Calibre's own PDF engine: in the PDF input options, the manual recommends it, because it removes most running headers and footers by itself.
- Search & replace: catches the headers, footers and page numbers that are left.
- Line un-wrapping factor (PDF input): joins lines that belong to one paragraph. It fixes broken paragraphs, not mixed columns.
- Nothing in the settings fixes the column order. Calibre's manual says it in its own words: “Complex, multi-column, and image based documents are not supported.” If the converter read across the columns, start from a source with one column: the paper's HTML version, if it has one.
For an e-reader: k2pdfopt
If the EPUB is meant for a Kindle or a Kobo, k2pdfopt is the better fit. It finds the columns and re-cuts each page into a PDF sized to the e-reader's screen, one column at a time. The result is a PDF, not an EPUB. By default its text is a picture of the original, so you can't resize it; its native mode keeps the text selectable, but still can't rewrap it. More in PDF reflow on an e-reader.
If you only want to read it
Converting is worth it when you need the EPUB file. To read a paper on your phone, you don't need one: a reflowing reader works on the PDF itself. PDFreflow finds the columns, drops the headers and footers, and keeps formulas and figures as pictures in the text. How it compares with converting: PDFreflow vs Adobe Liquid Mode vs converting to EPUB.
It's not perfect on every layout yet. If a page reads wrong, long-press the text and send feedback from the app. I read every report.
Try it
Free to try: the first 30 pages of every document are free. Longer documents: €9.99 Early Bird for the one-time Premium unlock. Pay once, read everything: all your documents, now and in the future. No subscription, nothing to pay per document.
Works with text-based PDFs. Scanned documents aren't supported.