ebookformate

ebookformate refers to the various file formats used to store and distribute electronic books. Each format defines how text, images, metadata, and sometimes interactive features are encoded, how content is rendered on devices, and whether protections such as digital rights management (DRM) are applied.

Formats are commonly classified as reflowable or fixed-layout. Reflowable formats, such as EPUB and MOBI, allow the text to reflow to fit different screen sizes and font preferences, improving readability on small devices. Fixed-layout formats, like PDF, preserve page geometry and layout, which can be important for complex designs, comics, or textbooks but may be less adaptable to different screens. DRM is often a consideration, with many popular formats offered in both DRM-protected and DRM-free forms depending on the platform.

The most widely used open standard is EPUB, maintained by industry groups and now under the W3C umbrella. EPUB supports reflowable text, navigational structures, metadata, and accessibility features, making it common for a broad range of devices and apps. Amazon’s Kindle ecosystem uses MOBI and its successors (such as AZW/AZW3), which are optimized for Kindle hardware and apps and commonly deployed with DRM. PDF remains prevalent for distributing print-style documents but is generally less suited for small screens due to its fixed layout.

In practice, publishers and distributors often convert content between formats to reach different devices and markets. Readers may choose formats and devices based on compatibility, features, and DRM policies, as well as accessibility considerations.