eBook Formats


List of Common eBook Formats

Format Description Extentions
AZW Amazon's proprietary format; similar to MOBI. With this format, DRM protected files cannot be viewed by other devices. If it's an unprotected file, such as personal documents converted to AZW, the file extension can be changed to .prc and .mobi to view with different devices. .azw
BBEB Sony's proprietary format; stands for Broadband eBook. The main file type variants: .lrx for DRM protected; .lrf for non-encrypted; and .msd for dictionaries. .lrs
CHM Stands for compressed HTML. Used for large reference manuals and help documentation. Windows uses CHM for help files. .chm
DJVU A format by Lizardtech; widely used for scientific publications. DjVu uses advanced compression techniques for high-resolution images of scanned documents, digital documents, and photographs. Its compression ratio is about 10x better than PDF, and retains the same high quality. .djvu
DOC Not to be confused with PalmDOC, .doc is Microsoft word's format. Can be converted to other file types for improved ebook viewing. .doc
EPUB A popular open ebook standard defined by the International Digital Publishing Forum (IDPF). EPUB is based on XHTML and XML and is one of the more popular ebook formats. Adobe Digital Editions uses EPUB formatting. .epub
FB2 Stands for Fiction Book version 2; based on XML. FB2's main focus is to preserve accurate ebook structure and to make it easy to convert to other popular ebook formats. .fb2
HTML Stands for HyperText Markup Language; the language used by all internet websites that any browser can read. .html
LIT The native format used for Microsoft Reader. .lit
LRF Sony's proprietary format. See BBEB. .lrf
MOBI A widely used, very popular format by Mobipocket; also can be .prc. Mobipocket's software can convert .chm, .doc, .html, .ocf, .pdf, .rtf, and .txt files to this format. .mobi
PDB Stands for palm database. This format is widely used for cellphones (BlackBerry, iPhone), and Palm devices. Plucker, PalmDOC, iSilo, eReader, zTXT, and many more. .pdb
PDF Stands for Portable Document Format. The most widely used file type. Created by Adobe. Most ebook readers support PDF, but it's a challenge to display a 14" diagonal page on a 6" diagonal screen. There are conversion softwares, such as Calibre, that reformat PDF to display better on ebook readers. .pdf
PRC Stands for Palm Resource Compiler; aka MOBI. .prc
RTF Stands for Rich Texture Format; one of the most widely interchangeable ebook formats and supported by most ebook readers and word processors. RTF retains special characters and text formatting. .rtf
TXT Plain text files don't retain special characters or formatting; basic notepad style. .txt
WOLF The proprietary format for Hanlin ebook readers, aka BeBook. .wol

DRM Protected Files

Digital Rights Management or DRM is a scheme that controls access to copyrighted material using technological means. It may refer to the usage of proprietary software, hardware, or any type of content: music tracks, video files, ebooks, games, DVD movies, emails, documents, etc. DRM is all about copyright protection.