How to open .EPUB files (e-books) on Android, Windows and Linux

You’ve downloaded a free classic from Project Gutenberg, bought a DRM-free novel from an independent publisher, or been given a course textbook as an .epub. It’s the most common e-book format in the world, yet Windows no longer has a reader built in, and many Android phones don’t either.

Folders has a book reader for EPUB files on Android, Windows and Linux. It’s free, works offline, and picks up where you left off.

What is an .epub file?

EPUB is the open standard for e-books. It was created by the International Digital Publishing Forum (IDPF) and is now maintained by the W3C, the body behind web standards. That heritage shows: an EPUB is essentially a small website packed into a ZIP archive.

Inside every EPUB you’ll find:

• a mimetype file containing application/epub+zip, so readers know what it is;
• the chapters as XHTML pages, styled with CSS;
• pictures, and sometimes embedded fonts;
• a package file (.opf) that lists everything and sets the reading order;
• a navigation file with the table of contents.

Most EPUBs are reflowable: the text rewraps to fit any screen and any text size, which is why they read better on a phone than a PDF. Fixed-layout EPUBs, used for picture books, cookbooks and some comics, keep every page exactly as designed. EPUB 3, the current version, is built on HTML5 and supports audio, video and better handling of many languages; plenty of books are still in the older EPUB 2.

Apple Books, Google Play Books, Kobo and most public libraries use EPUB. Amazon’s Send to Kindle service also accepts EPUB files now and converts them for the Kindle.

How to open an .epub file with Folders

On Android

1. Install Folders from the download section and allow it to access your files.
2. Find the book. Downloads from your browser land in Download; search for .epub to list every book in a folder.
3. Tap the book. It opens in the book reader at the first page, or where you stopped last time.
4. If the EPUB came by email or chat, tap it and pick Open with → Folders.

On Windows and Linux

1. Install Folders, browse to your books and open one.
2. On Windows, you can also right-click any .epub in File Explorer and choose Open with → Folders; the installer adds it there.
3. On a wide window, the reader can show two pages side by side, like an open book.

What you can do with it in Folders

• Table of contents and bookmarks. Jump to any chapter, and bookmark pages you want to come back to.
• Search in book finds a word or name across the whole text.
• Reading settings. Change the text size, the margins and the theme (light, dark and others) until it’s comfortable.
• Scroll or pages. Read as one long scroll, or turn pages like a book. On wide screens, two-page spreads.
• Previous and next chapter buttons for quick moves.
• It remembers where you stopped, so you can close a book and come back to the same spot.

Other ways to open .epub files

• Calibre: free e-book manager for Windows and Linux, with a viewer and converters.
• Thorium Reader: a free reader for Windows and Linux that also handles library books protected with LCP.
• Google Play Books: upload your EPUB and read it on any device signed in to your Google account.
• Kindle: send the EPUB through Amazon’s Send to Kindle and read the converted copy.

Problems opening an .epub file?

• You have an .acsm file, not an .epub. Libraries and some stores give you an ACSM file: a small licence ticket, not the book. Adobe Digital Editions uses it to download the real EPUB, which is locked with Adobe DRM. Folders can’t open either; use Adobe Digital Editions or a reader app that supports Adobe DRM.
• The book has DRM. Books locked with copy protection (Adobe DRM, Apple’s FairPlay on books bought in Apple Books, or LCP) won’t open in Folders, and it tells you the book is protected. DRM-free EPUBs, which many publishers and all public-domain sites offer, open normally.
• Microsoft Edge doesn’t open it any more. The old Edge had an EPUB reader; the current, Chromium-based Edge doesn’t. Use a reader app such as Folders instead.
• The book looks broken. Badly made EPUBs exist. The W3C’s EPUBCheck tool reports what’s wrong, and converting the book EPUB to EPUB in Calibre often repairs it.

Questions people ask

How do I open an EPUB file on Windows 11? Windows 11 has no EPUB reader built in. Install Folders (or Calibre, or Thorium Reader) and open the file there.

Can I read EPUB on a Kindle? Yes, through Amazon’s Send to Kindle, which converts the book. Books with DRM from other stores can’t be sent this way.

How do I convert EPUB to PDF? Folders reads EPUB but doesn’t convert it. Calibre can convert EPUB to PDF, MOBI, AZW3 and other formats for free.

EPUB vs PDF: what’s the difference? EPUB text reflows to fit the screen and your chosen text size, which suits phones. A PDF keeps fixed pages, which suits printing and documents where the layout matters.

More reading help: how to open .MOBI and Kindle files and how to open .FB2 books, or see all 382 file types Folders opens.