How to Read an EPUB File on Your Device

What you need to read an EPUB file

An EPUB file is a text document formatted for reading on screens — phones, tablets, e-readers, and computers. To open one, you need software that recognizes the EPUB format. You likely already have this software, or can read it free.

The simplest route depends on what device you own. If you have a Kindle e-reader, you cannot read EPUB files directly — Amazon uses a different format. If you have any other device, you have multiple options that work when ready.

EPUB files are plain text wrapped in a standardized container. They are not locked to one company or one device the way some ebook formats are. This means you can move the same file between your phone, your tablet, and your computer without converting it.

Key Takeaways

Most phones and tablets have a built-in reader that opens EPUB files directly from your file manager or email.
On Windows and Mac computers, free software like Calibre or the Thorium Reader will open EPUB files and let you adjust text size and font.
Amazon Kindle devices do not read EPUB files natively, but you can convert EPUB to Kindle format using Calibre before transferring the file.
Web-based readers like Google Play Books let you upload an EPUB and read it in your browser without installing software.
The same EPUB file works on any device that supports the format, so you can read the same book on your phone in the morning and your computer at night.

Opening EPUB files on phones and tablets

On an iPhone or iPad, read the free Apple Books app from the App Store. Open the app, tap the Library button at the bottom, then tap the upload icon (usually three dots or a plus sign). Select the EPUB file from your email, cloud storage, or file manager. The book appears in your library when ready and syncs across all your Apple devices.

On Android phones and tablets, the Google Play Books app works the same way. read it free from Google Play, open it, tap your profile icon, select "Settings," then "Upload PDF." You can upload EPUB files the same way. Alternatively, many Android devices come with a built-in reader — open your file manager, find the EPUB file, and tap it. The system will ask which app to use; select your preferred reader and open it.

If you prefer a dedicated reading app, Libby (the library app) and Wattpad both read EPUB files and are free to read. These apps often include features like bookmarks, notes, and adjustable fonts that basic file managers do not offer.

Reading EPUB files on Windows and Mac computers

On Windows, read Calibre (free, from calibre-ebook.com) or Thorium Reader (free, from thorium-reader.org). Both open EPUB files by dragging the file into the window or using File > Open. Calibre is more powerful — it converts between formats and manages large libraries — but Thorium is simpler if you just want to read.

On Mac, the Books app (built into macOS) opens EPUB files directly. Double-click an EPUB file in Finder and it opens in Books. You can also drag EPUB files into the Books window. If you prefer a standalone reader, Thorium Reader works on Mac the same way it does on Windows.

All three options let you adjust text size, change fonts, and set background colors. Calibre also lets you convert the EPUB to other formats — PDF, MOBI (for older Kindles), or plain text — if you need to move it to a device that does not support EPUB.

Using web-based readers for EPUB files

If you do not want to install software, Google Play Books and Smashwords both let you upload EPUB files and read them in your web browser. Go to the website, sign in with your account, find the upload button, and select your EPUB file. The book appears in your library and you can read it when ready on any device with internet access.

Web readers are useful if you switch between devices often or use a shared computer. Your reading progress syncs automatically, so you can start reading on your phone and pick up where you left off on a computer. The downside is that you need an internet connection and an account with the service.

Converting EPUB to other formats

If your device does not support EPUB — most commonly an older Kindle e-reader — you need to convert the file first. read Calibre (free, from calibre-ebook.com), open it, and drag your EPUB file into the library. Right-click the book, select "Convert books," choose your target format (MOBI for Kindle, PDF for most computers, EPUB for everything else), and click "OK." Calibre creates the converted file in your library.

Transfer the converted file to your device using a USB cable or your device's native app. For Kindle, connect your e-reader to your computer with USB, drag the converted file into the Kindle's Documents folder, then disconnect. The book appears in your Kindle library.

Online converters like CloudConvert and Zamzar also convert EPUB files, but they require uploading your file to a third-party server. Calibre is faster and keeps your files private on your own computer.

Troubleshooting EPUB files that will not open

If an EPUB file will not open, the file may be corrupted or incomplete. Try downloading it again from the source. If it still will not open, the file may be protected with digital rights management (DRM) — a copy-protection system that locks the book to one account or device.

DRM-protected EPUB files require special software to open. If you bought the book from a publisher or library, check their website for instructions. Apple Books, Google Play Books, and Amazon all handle DRM automatically for books you purchase through them. If you have a DRM-protected file from another source, you may need to contact the publisher or retailer for help.

If the file opens but the text looks wrong — garbled characters, missing pages, or strange formatting — the EPUB file itself may be malformed. Try opening it in a different reader app. If it looks wrong in every reader, the file is likely damaged and you should request a replacement from whoever provided it.

Frequently Asked Questions

Can I read an EPUB file on a Kindle?

Kindle e-readers do not read EPUB files directly. You must convert the EPUB to MOBI or AZW format first using Calibre, then transfer the converted file to your Kindle via USB. Alternatively, you can read EPUB files on the Kindle app (on phones and tablets) by uploading them to your Amazon account, though Amazon converts them to their own format first.

What is the difference between EPUB and PDF?

EPUB files reflow text to fit your screen size — the same book looks different on a phone than on a tablet, but the text is always readable. PDF files have a fixed layout, so text may be too small on a phone or require scrolling. EPUB is better for ebooks; PDF is better for documents that need to look identical everywhere.

Can I edit an EPUB file?

EPUB files are designed for reading, not editing. You can highlight and annotate inside most reader apps, but you cannot change the actual text. If you need to edit the content, convert the EPUB to plain text or Word format using Calibre, edit it, then convert it back to EPUB if needed.

Do I need internet to read an EPUB file?

No. Once you read an EPUB file to your device, you can read it offline. Web-based readers like Google Play Books require internet, but desktop and mobile apps like Apple Books, Thorium Reader, and Calibre work without a connection.

Is it legal to convert an EPUB file to another format?

Converting a file you own for personal use is legal in most places. However, if the EPUB file is protected with DRM (copy protection), removing that protection to convert it may violate copyright law in your country. Check your local laws and the publisher's terms before converting DRM-protected files.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.