What EPUB Is
EPUB is the industry-standard file format for e-books. Unlike PDF, which preserves a fixed page layout, EPUB produces reflowable content that adapts to the reader's screen size, font preferences, and device settings. This makes it the preferred format for distributing books across e-reader platforms and apps.
When you export your book as EPUB, Authorio packages your content, cover, chapter structure, and formatting into a single .epub file that is ready for distribution.
Compatible Devices and Apps
EPUB files work across a wide range of devices and reading applications:
- Apple Books -- The default reading app on iPhone, iPad, and Mac
- Kobo -- Kobo e-readers and the Kobo app
- Google Play Books -- Available on Android, iOS, and web
- Nook -- Barnes & Noble's e-reader and app
- Calibre -- Desktop e-book management software that reads and converts EPUB files
- Most third-party reading apps -- Apps like Aldiko, Lithium, and ReadEra support EPUB natively
EPUB is also the required or preferred upload format for many digital publishing and distribution platforms, making it a good choice if you plan to sell your book through multiple channels.
When to Use EPUB
Choose EPUB when your readers will consume your book on screens rather than on paper:
- Distributing to e-reader platforms -- If you are listing your book on Apple Books, Kobo, Google Play Books, or other digital storefronts, EPUB is typically the expected format.
- Offering a digital download -- If your audience reads on tablets, phones, or dedicated e-readers, EPUB provides a better reading experience than PDF because the text reflows to fit any screen.
- Maximizing compatibility -- EPUB is supported by more devices and apps than any other e-book format.
If you are publishing specifically on Amazon Kindle, use the Kindle (KDP) export instead, which is optimized for Amazon's requirements.
Downloading Your EPUB
Open the export panel, select EPUB, and click the export button. Authorio generates the file with your content, cover, and formatting applied. Once ready, the .epub file downloads to your device. You can re-export at any time after making edits.
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