How do you open an EPUB file, and what changes in a PDF?
How to open a downloaded .epub on each device, and when converting it to PDF makes sense
You downloaded an e-book from a publisher's site, a free classics archive or the extra materials of a course. The file is called book.epub; you double-click it on your computer and either nothing happens or Windows asks which app to use. Perhaps you want to print it, put it on an older relative's tablet or read it on a Kindle, and you assume it has to become a PDF first.
EPUB is the common format for e-books, and your file is very likely fine. It won't open because there is no e-book reader installed on that device. This guide first shows how to read the book without converting anything, then when a PDF actually makes sense and why the pages never look quite like the book once converted. There is also an honest limit: copy-protected books you have bought cannot be converted anywhere, and the reason is explained below.
Try reading it first, without converting: the route for each device
If all you want is to read the book, there is no need to convert it. An app built for EPUB shows it at its most comfortable: you can enlarge the text, switch to night mode and keep your place. The shortest route depends on your device:
| Device | What to do |
|---|---|
| iPhone and iPad | Find the book in the Files app, tap Share and choose Books |
| Mac | Double-click the file; Apple's Books app opens it |
| Android phone | Open it with Google Play Books, or email it to yourself and upload the attachment to Play Books |
| Windows PC | There is usually no reader built in; install a free e-book program such as Calibre, or convert the book to PDF |
| Kindle | Don't copy it over USB; send it with Amazon's Send to Kindle service, which accepts .epub |
| Printer | It can't print directly; convert to PDF first |
An EPUB has no pages: what reflowable layout means
In a printed book every page is set once, at the printer. An EPUB has no fixed pages at all; the book is stored paragraph by paragraph, much like a web page; it is the reading app that lays that text out afresh for whatever screen opens it. This is called reflowable layout. Make the text bigger and the lines get shorter, so the book spreads over more pages; turn the phone sideways and the page count changes again.
That is why telling a friend to "look at page 42" doesn't work with an EPUB: page 42 on their screen is somewhere else. Reading apps often show a percentage or a location number instead of a page for exactly this reason.
Why the PDF never looks exactly like the book
Converting to PDF means freezing reflowable text at one paper size. The converter takes the book's paragraphs and sets them once, on the paper you choose, at a given text size. The resulting pages are not the ones you saw in your reading app, because there were no fixed pages there to begin with. That is also why the page count rarely matches the printed edition.
The EPUB to PDF converter on this site keeps the reading order, chapter headings, lists, tables and JPEG and PNG images, and starts each chapter on a new page. The book's own fonts and decoration don't come across; the text is set in a single typeface. That typeface only covers the Latin alphabet: in an Arabic, Russian or Greek book those letters turn into question marks in the PDF. If you need such a book's text, use the EPUB to TXT converter instead; plain text keeps every alphabet intact.
Choose the paper size by where the PDF is going. For a printer in the US or Canada pick Letter, for one elsewhere pick A4; to read the PDF on a tablet or phone, A5, close to a paperback page, is far easier on the eyes. Fixed-layout EPUBs such as comics and illustrated children's books lose their page design and are turned into flowing content; when the look is the point, open those in a reading app instead of converting.
Don't convert to PDF just to read on a Kindle
A common mistake is to turn an EPUB into a PDF in order to get it onto a Kindle. Because a PDF has fixed pages, it looks tiny on a six-inch Kindle screen and you can't make the text bigger. Since 2022 Amazon's Send to Kindle service has accepted .epub files and delivers the book to the device in its own format, so the text-size controls keep working.
Sending is simple: email the file as an attachment to the Send to Kindle address linked to your Kindle, or upload it on Amazon's Send to Kindle page. You'll find your address in your Amazon account under the content and devices settings. The opposite direction isn't offered here: .azw or .kfx books bought for Kindle are not EPUBs, and most of them are copy-protected.
Why copy-protected (DRM) books can't be converted
Most e-books you buy or borrow from a library are copy-protected; this is called DRM. The chapters of such a book are stored encrypted, and only the seller's app, linked to your account, holds the key. The converters on this site check the encryption record inside the package when they open a book; if the content is encrypted, they say plainly that it is copy-protected instead of producing an empty or garbled PDF. They don't remove the protection, and we don't describe how to. Read such a book in the seller's app, or get a DRM-free edition from the publisher.
One common mix-up: if the file you got after buying ends in .acsm, what you have is not the book. That small file is more like a download permit; opened in Adobe Digital Editions, it fetches the actual book in protected form. Public-domain classics from free archives, books that authors give away on their own sites, and EPUBs you wrote yourself and exported from LibreOffice Writer are unprotected and convert without trouble.
Printing the book, listening to it, or going the other way
If you want to print the book, PDF is the right format: pick your printer's paper size in the EPUB to PDF converter, leave the cover switched on and print the result like any other file. If you only need the words, for example to feed a text-to-speech app or to search for a quotation, the EPUB to TXT converter writes the chapters in order as plain text; images and formatting go, the text stays.
Sometimes the direction is reversed: you have a PDF of lecture notes that is hard to read on a phone and want it as a book whose text flows to fit the screen. The PDF to EPUB converter takes the document's text and splits it into chapters, giving you an e-book where the text size can be changed. Tables and multi-column pages lose their layout on the way, and a scanned PDF yields no text at all.
Frequently asked questions
Why won't an EPUB file open on Windows?
Windows usually comes without an e-book reader, so the system doesn't know which program to hand the file to. You can install a free e-book program such as Calibre, or convert the book to PDF on this site and open it in any PDF viewer.
Why does the PDF have a different number of pages from the book?
An EPUB has no fixed pages, so the book is laid out again for the paper size and text size you pick. A5 gives more pages, A4 or Letter fewer, and none of them match the page numbers of the printed edition. When quoting, citing the chapter is safer than citing a page.
I downloaded an .acsm file. Where is my book?
That file is not the book itself but a permit for downloading a protected copy. Opened in Adobe Digital Editions, it fetches the real book, which, being protected, can only be read in that kind of program; the converters on this site can't open it.
Can I convert an Arabic or Russian EPUB to PDF?
The PDF converter can only draw Latin letters, so those characters become question marks. To keep the text, use the EPUB to TXT converter: a plain text file stores every alphabet as it is and opens on any device.
Is my book uploaded to a server?
No. All the work is done by your browser, on your own device, and the book is not sent anywhere. Go offline once the page has opened, if you like: the PDF is still produced.
Last updated: October 12, 2026