Reading an A4 PDF on a 6-inch e-reader means zooming and scrolling sideways on every page. An EPUB fixes that, because the reader sets the text to fit its own screen and your chosen font size. The catch is that a PDF does not store paragraphs, only glyphs placed at coordinates on a page. A converter has to guess where a paragraph ends, which lines are a running header and what belongs in which column. That guess is good for a novel and poor for a textbook. Here is what to expect.
Why people convert PDF to EPUB
- Reading on an e-reader or phone with adjustable font size, night mode and the device's dictionary.
- Kindle. Send to Kindle has accepted EPUB since 2022 and turns it into a Kindle book with reflowing text, while a PDF arrives as fixed pages.
- Kobo, PocketBook, Tolino, Apple Books all read EPUB natively.
- Long reports and manuscripts you want to read on the go rather than at a desk.
How the conversion works
Our converter reads every line of text in the PDF with its position, then joins the lines back into paragraphs based on their spacing, length and indentation. It scans the first pages for repeating headers and footers and tries to drop them. Raster images are extracted and placed in the text. The result is an EPUB 2 file, the version with the widest reader compatibility, and the first page of the PDF is usually rendered as the cover.
Even the calibre manual calls PDF one of the worst formats to convert from. Our converter has these limits:
| Type of PDF | What you get |
|---|---|
| Novel, essay, single-column report | Good, readable EPUB; occasional stray page numbers |
| Two-column journal article | Text usually right, but reading order can jump between columns |
| Textbook with boxes, sidebars, tables | Tables become loose lines of text, boxes end up in odd places |
| Vector charts and diagrams | Not extracted, they disappear |
| Mathematical formulas | Broken into separate characters |
| Scanned PDF without a text layer | No text, at best page images; we do not run OCR on PDFs |
| PDF that needs a password to open | Conversion fails |
Hyperlinks and the PDF's bookmarks are not carried over, and fonts are not either: the EPUB uses whatever font the reader is set to.
Common problems and fixes
"PDF to EPUB formatting messed up"
Check the PDF type in the table above. Complex layouts cannot be reconstructed automatically by any tool without manual work. If you have the original document (DOCX, ODT, RTF), convert that instead. A word processor file contains real paragraphs, headings and tables, and it converts into a much cleaner EPUB than any PDF.
"Line breaks in the middle of sentences"
The paragraph detection guessed wrong, typically in PDFs with very short or uneven lines (poetry, lists, centred text). In the free calibre app the PDF input options (line unwrap factor, header and footer patterns) can be tuned by hand; they are described in the calibre manual.
"Page numbers or the book title appear in the text"
Header and footer detection works when they repeat at the same position. Alternating headers on odd and even pages, or headers in the margin, can slip through.
"The EPUB is empty" or "only images"
The PDF is a scan. Run it through OCR first (many scanners and PDF editors can add a text layer), then convert the result.
Format background
PDF was introduced by Adobe in 1993 and standardised as ISO 32000-1 in 2008; PDF 2.0 is ISO 32000-2. EPUB comes from the International Digital Publishing Forum (EPUB 2 in 2007, EPUB 3 in 2011) and has been maintained by the W3C since 2017, currently as EPUB 3.3. The Library of Congress format descriptions for PDF 1.7 and EPUB cover the details.
DRM and alternatives
A PDF bought with Adobe DRM cannot be converted, and we do not remove DRM. PDFs that only restrict printing or copying still convert.
Sometimes no conversion is needed: Kindle, Kobo and PocketBook devices display PDF directly, and for diagrams, forms or exact layout that is the better choice. If you need to edit the text rather than read it, PDF to Word is the more useful target. And when you go the other way, from e-book to print, see EPUB to PDF.