The following is a comparison of e-book formats used to create and publish e-books.
The EPUB format is the most widely supported e-book format, supported by most e-book readers, including Kobo eReader devices, Amazon Kindle devices being an exception. Most e-book readers also support the PDF and plain text formats. E-book software, like the cross-platform Calibre, can be used to convert e-books from one format to another, as well as to create, edit and publish e-books.
Format descriptions Formats available include, but are not limited to:
Broadband eBooks (BBeB)
Format: Sony media Published as: .lrf, .lrx The digital book format originally used by Sony Corporation. It is a proprietary format, but some reader software for general-purpose computers, particularly under Linux (for example, Calibre's internal viewer), have the capability to read it. The LRX file extension represents a DRM-encrypted e-book. More recently, Sony has converted its books from BBeB to EPUB and is now issuing new titles in EPUB.
Comic Book Archive file
Format: compressed images Published as:.cbr (RAR), .cbz (ZIP), .cb7 (7z), .cbt (TAR), .cba (ACE)
Compiled HTML Format: Microsoft Compiled HTML Help Published as: .chm CHM format is a proprietary format based on HTML. Multiple pages and embedded graphics are distributed along with metadata as a single compressed file. The indexing is both for keywords and for full text search.
DAISY – ANSI/NISO Z39.86 Format: DAISY Published as:
The Digital Accessible Information SYstem (DAISY) is an XML-based open standard published by the National Information Standards Organization (NISO) and maintained by the DAISY Consortium for people with print disabilities. DAISY has wide international support with features for multimedia, navigation and synchronization. A subset of the DAISY format has been adopted by law in the United States as the National Instructional Material Accessibility Standard (NIMAS), and K-12 textbooks and instructional materials are now required to be provided to students with disabilities.
DAISY is already aligned with the EPUB technical standard, and is expected to fully converge with its forthcoming EPUB3 revision.
Djvu Format: DjVu Published as: .djvu DjVu is a format specialized for storing scanned documents. It includes advanced compressors optimized for low-color images, such as text documents. Individual files may contain one or more pages. DjVu files cannot be re-flowed.
The contained page images are divided in separate layers (such as multi-color, low-resolution, background layer using lossy compression, and few-colors, high-resolution, tightly compressed foreground layer), each compressed in the best available method. The format is designed to decompress very quickly, even faster than vector-based formats.
The advantage of DjVu is that it is possible to take a high-resolution scan (300–400 DPI), good enough for both on-screen reading and printing, and store it very efficiently. Provided the images are reasonably clean and the most aggressive compression settings are used, a couple hundred 600-DPI black-and-white text scans can be stored in less than a megabyte.
DOC Format: Microsoft Word Published as: .doc
DOC is a document file format that is directly supported by few e-book readers. Its advantages as an e-book format is that it can be easily converted to other e-book formats and it can be reflowed. It can be easily edited using Microsoft software, and any of several other programs. Note that the format has changed several times since its original release, and there are numerous incompatibility difficulties between various releases and the assorted programs which attempt to read / write the format.
DOCX Format: Microsoft Word (XML) Published as: .docx
DOCX is a document file format that is directly supported by few e-book readers. Its advantages as an e-book format are that it can be easily converted to other e-book formats and it can be reflowed. It can be easily edited.
EPUB
Format: EPUB 3 (open eBook) Published as: .epub
The EPUB (formerly OEBPS) format is a technical standard for e-books created by the International Digital Publishing Forum (IDPF).
The format has gained mass popularity as the most popular vendor-independent XML-based e-book format. The format can be read by Kobo eReader devices, BlackBerry devices, Apple's Apple Books app running on Macintosh computers and iOS/iPadOS devices, Google Play Books app running on Android and iOS/iPadOS devices, Barnes & Noble Nook, Sony Reader, BeBook, Bookeen Cybook Gen3 (with firmware v2 and up), Adobe Digital Editions, Lexcycle Stanza, FBReader, PocketBook eReader, Aldiko, the Mozilla Firefox add-on EPUBReader, Lucifox, Okular and other reading apps. Amazon Kindle devices cannot read books in EPUB format, but Send to Kindle service can convert .epub files to Kindle File Format.
Adobe Digital Editions uses .epub format for its e-books, with digital rights management (DRM) protection provided through their proprietary ADEPT mechanism. The ADEPT framework and scripts have been reverse-engineered to circumvent this DRM system.
eReader Format: Palm Media Published as: .pdb
eReader is a freeware program for viewing Palm Digital Media electronic books which use the pdb format used by many Palm applications. Versions are available for Android, BlackBerry, iOS, Palm OS (not webOS), Symbian, Windows Mobile Pocket PC/Smartphone, and macOS. The reader shows text one page at a time, as paper books do. eReader supports embedded hyperlinks and images. Additionally, the Stanza application for the iPhone and iPod Touch can read both encrypted and unencrypted eReader files.
The program supports features like bookmarks and footnotes, enabling the user to mark any page with a bookmark and any part of the text with a footnote-like commentary. Footnotes can later be exported as a Memo document.
On July 20, 2009, Barnes & Noble made an announcement implying that eReader would be the company's preferred format to deliver e-books. Exactly three months later, in a press release by Adobe, it was revealed Barnes & Noble would be joining forces with the software company to standardize the EPUB and PDF e-book formats. Barnes & Noble e-books are now sold mostly in EPUB format.
FictionBook (fb2) Format: FictionBook Published as: .fb2
FictionBook is an XML-based e-book format, supported by free readers such as PocketBook eReader, FBReader, Okular, CoolReader, BeBook and STDU Viewer.
The FictionBook format does not specify the appearance of a document; instead, it describes its structure and semantics. All e-book metadata, such as the author name, title, and publisher, is also present in the file. Hence the format is convenient for automatic processing, indexing, and e-book collection management. This is also convenient for book storage for later automatic conversion into other formats.
Founder Electronics Format: Apabi Reader Published as: .xeb, .ceb APABI is a format devised by Founder Electronics. It is a popular format for Chinese e-books. It can be read using the Apabi Reader software, and produced using Apabi Publisher. Both .xeb and .ceb files are encoded binary files. The ILiad e-book device includes an Apabi viewer.
Hypertext Markup Language Format: Hypertext Published as: .htm, .html (and typically auxiliary images), .js, .css HTML is the markup language used for most web pages. E-books using HTML can be read using a Web browser. The specifications for the format are available without charge from the W3C.
HTML adds specially marked meta-elements to otherwise plain text encoded using character sets like ASCII or UTF-8. As such, suitably formatted files can be, and sometimes are, generated by hand using a plain text editor or programmer's editor. Many HTML generator applications exist to ease this process and often require less intricate knowledge of the format details involved.
HTML on its own is not a particularly efficient format to store information in, requiring more storage space for a given work than many other formats. However, several e-Book formats including the Amazon Kindle, Open eBook, Compiled HTML, Mobipocket and EPUB store each book chapter in HTML format, then use ZIP compression to compress the HTML data, images, metadata and style sheets into a single, significantly smaller, file.
HTML files encompass a wide range of standards and displaying HTML files correctly can be complicated. Additionally many of the features supported, such as forms, are not relevant to e-books.
iBook (Apple) Format: iBook Published as: .ibooks The .ibooks format was created with the free iBooks Author e-book layout software from Apple Inc. This proprietary format was based on the EPUB standard, with some differences in the CSS tags used in an ibooks format file, this making it incompatible with the EPUB specification. The End-User Licensing Agreement (EULA) included with iBooks Author states that "If you want to charge a fee for a work that includes files in the .ibooks format generated using iBooks Author, you may only sell or distribute such work through Apple". The "through Apple" will typically be in the Apple Apple Books store. The EULA further states that "This restriction does not apply to the content of such works when distributed in a form that does not include files in the .ibooks format." Therefore, Apple did not included distribution restrictions in the iBooks Author EULA for ibooks format e-books created in iBooks Author that are made available for free, and it does not prevent authors from re-purposing the content in other e-book formats to be sold outside the iBookstore. The software supported import and export functionally for three formats. ibook, Plain text and PDF. Versions 2.3 and later of iBooks Author support importing EPUB and exporting EPUB 3.0.
IEC 62448 Format: IEC 62448 Published as:
IEC 62448 is an international standard created by International Electrotechnical Commission (IEC), Technical Committee 100, Technical Area 10 (Multimedia e-publishing and e-book).
The current version of IEC 62448 is an umbrella standard that contains as appendices two concrete formats, XMDF of Sharp and BBeB of Sony. However, BBeB has been discontinued by Sony and the version of XMDF that is in the specification is out of date. The IEC TA10 group is discussing the next steps, and has invited the IDPF organization which has standardized EPUB to be a liaison. It is possible that the current version of EPUB or the EPUB3 revision may be added to IEC 62448. Meanwhile, a number of Japanese companies have proposed that IEC standardize a proposed new Japanese-centric file format that is expected to unify DotBook of Voyager Japan and XMDF of Sharp. This new format has not been publicly disclosed as of November 2010 but it is supposed to cover basic representations for the Japanese language. Technically speaking, the revision is supposed to provide a Japanese minimum set, a Japanese extension set, and a stylesheet language. These issues were discussed in the TC100 meeting held in October 2010 but no decisions were taken besides offering the liaison status to IDPF.
INF (IBM) Format: IBM & open source Published as: .inf IBM created this e-book format and used it extensively for OS/2 and other of its operating systems. The INF files were often digital versions of printed books that came with some bundles of OS/2 and other products. There were many other newsletters and monthly publications (e.g.: EDM/2) available in the INF format too.
The advantage of INF is that it is very compact and very fast. It also supports images, reflowed text, tables and various list formats. INF files get generated by compiling the markup text files — in the Information Presentation Facility (IPF) format — into binary files.