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Supports: EPUB
EPUB and PDF solve opposite problems. EPUB is a reflowable format: the text rewraps to fit whatever screen it lands on, which is why e-readers use it. PDF fixes the text onto pages of a set size so the file prints and looks identical everywhere. Convert EPUB to PDF when you need to print, annotate, submit or share a book that anyone can open without an e-reading app — and stay on EPUB when comfortable reading on phones and e-readers matters more. This page compares the two honestly, then walks through the conversion.
| Property | EPUB | |
|---|---|---|
| Full name | Electronic Publication | Portable Document Format |
| Standard | EPUB 3.3, a W3C Recommendation maintained by the Publishing Maintenance Working Group | ISO 32000 |
| Layout model | Reflowable by default; fixed-layout is possible for comics and picture books | Fixed pages — text and images sit at set coordinates |
| Text rewraps to screen size | Yes | No |
| Reader can change font and size | Yes, on any compliant reader | Only by zooming, which means panning on small screens |
| Prints predictably | Not really — pagination depends on the reader | Yes, that is its purpose |
| Underlying structure | A ZIP archive of XHTML, CSS and media files | A page-description document descended from PostScript |
| Annotation and form-filling | Reader-dependent, often limited | Broad support across desktop and mobile readers |
| Opens without special software | Needs an e-reader app or browser extension | Opens in effectively every OS, browser and phone |
| Best for | Reading on phones, tablets and e-readers | Printing, archiving, submitting, sharing a fixed layout |
.epub onto the page or click "+ Add Files" to browse. Several books can be queued and converted in one batch.| Element of the EPUB | In the resulting PDF |
|---|---|
| Body text and paragraph structure | Carried over, reflowed once onto fixed Letter pages |
| Headings, bold, italic, lists | Preserved as formatting on the page |
| Images and cover art | Embedded into the page flow |
| Table of contents | Chapter structure carries over as headings; live navigation depends on the source markup |
| Embedded fonts | Generally carried through; unusual or subsetted fonts may be substituted |
| Reflow and reader font controls | Lost — this is the whole point of a fixed-page format |
| Fixed-layout EPUBs (comics, picture books) | Most at risk of shifting, because pixel-exact placement rarely survives a move to a standard page size |
| DRM-protected books | Not convertible — the contents are encrypted |
Because that is the difference between the two formats. EPUB content is designed to reflow to the available screen space — the EPUB 3.3 specification treats reflowable presentation as the default and fixed layout as the special case. PDF fixes text onto pages of a defined size. The conversion has to pour the flowing text into set pages once and freeze it, which is exactly why the PDF prints and shares predictably, and exactly why it no longer rewraps on a small phone.
This conversion produces U.S. Letter pages (8.5 x 11 inches) with half-inch margins — the same default Calibre's own documentation specifies for PDF output. There is no page-size control on this page. If you need A4, most printers and print dialogs will scale a Letter PDF onto A4 with a small margin change, which is usually enough for a reading copy; for typeset-accurate A4 you would need a desktop conversion where the page size is configurable.
Yes for ordinary prose books: text, headings, bold and italic, lists and embedded images all carry through, and chapter headings remain visible in the flow. The books most likely to shift are highly designed ones — comics, magazines and fixed-layout children's titles that rely on pixel-exact placement — because that placement rarely maps cleanly onto a standard page. Check the first few pages of the PDF before printing a long book.
No, if it carries DRM. Store purchases and library loans are usually encrypted, and a converter cannot read the contents of an encrypted file — you will get an error rather than a PDF. DRM-free EPUBs (Project Gutenberg, Standard Ebooks, many indie publishers and most technical-book stores) convert without any trouble.
Usually not. Amazon's Send to Kindle has accepted EPUB files since its 2022 rollout, and it stopped accepting unprotected MOBI and AZW files in August 2022 — so EPUB is now the format to send. Kindles do display PDFs natively, but a fixed-page PDF does not reflow, so the text stays small unless you zoom and pan. Send the EPUB when you want a comfortable read, and reserve the PDF for printing. If you have an old Kindle-format file instead, MOBI to PDF handles that direction.
Fonts referenced by the book generally carry through into the PDF so the typography looks close to the original, and the base text size is set to 14 points for comfortable screen reading. Where a font is heavily subsetted or unusual, a substitute may be used — visually similar, but not identical. If exact typography is critical, compare a page of the PDF against the same page in an e-reader before you commit.
Run the finished file through our PDF compressor, which is the tool that actually applies Ghostscript-style compression levels to an existing PDF. That is a better route than re-converting, because it lets you trade image quality against size directly and see the result. Image-heavy books benefit the most; a plain-prose PDF is usually small enough to attach as-is.
You can, but expect a quality drop. Calibre's own manual is blunt about it: "PDF documents are one of the worst formats to convert from," because a PDF is a fixed page-and-position format with no reliable record of where one paragraph ends and the next begins. Keep the original .epub as your master rather than round-tripping. If you only have the PDF, PDF to EPUB will do the job, and EPUB to MOBI covers older Kindle-format needs. Whatever you upload here is encrypted in transit, processed on our servers, deleted automatically after a few hours, and never shared or made public.