The Web Open Font Format (WOFF) is a font format for use in web pages. WOFF files are

OpenType OpenType is a format for scalable computer fonts. It was built on its predecessor TrueType, retaining TrueType's basic structure and adding many intricate data structures for prescribing typographic behavior. OpenType is a registered trademark ...

TrueType TrueType is an outline font standard developed by Apple in the late 1980s as a competitor to Adobe's Type 1 fonts used in PostScript. It has become the most common format for fonts on the classic Mac OS, macOS, and Microsoft Windows operating ...

fonts, with format-specific compression applied and additional

XML Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable ...

metadata added. The two primary goals are first to distinguish font files intended for use as web fonts from fonts files intended for use in desktop applications via local installation, and second to reduce web font latency when fonts are transferred from a server to a client over a network connection.

Standardization

The first draft of WOFF 1 was published in 2009 by Jonathan Kew, Tal Leming, and Erik van Blokland, with reference conversion code written by Jonathan Kew. Following the submission of WOFF to the

World Wide Web Consortium The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web. Founded in 1994 and led by Tim Berners-Lee, the consortium is made up of member organizations that maintain full-time staff working ...

(W3C) by the

Mozilla Foundation The Mozilla Foundation (stylized as moz://a) is an American non-profit organization that exists to support and collectively lead the open source Mozilla project. Founded in July 2003, the organization sets the policies that govern development, ...

Opera Software Opera is a Norwegian multinational technology company and subsidiary of Kunlun that specializes in web browser development, fintech, as well as services such as Opera News and YoYo Games. The company's total user base, including users of its ...

and

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washin ...

in April 2010, the W3C commented that it expected WOFF to soon become the "single, interoperable format" supported by all browsers. The W3C published WOFF as a working draft in July 2010. The final draft was published as a

W3C Recommendation The World Wide Web Consortium (W3C) is the main international standards organization for the World Wide Web. Founded in 1994 and led by Tim Berners-Lee, the consortium is made up of member organizations that maintain full-time staff working t ...

on 13 December 2012. WOFF 2.0, with reference code provided by Google, has an improved compression scheme, using

Brotli Brotli is a lossless data compression algorithm developed by Google. It uses a combination of the general-purpose LZ77 lossless compression algorithm, Huffman coding and 2nd-order context modelling. Brotli is primarily used by web servers and ...

for byte-level compression, and became a W3C Recommendation in March 2018.

Specification

WOFF is a wrapper containing SFNT-based fonts (

) that have been compressed using a WOFF-specific encoding tool so they can be embedded in a Web page. WOFF Version 1 uses the widely available

zlib zlib ( or "zeta-lib", ) is a software library used for data compression. zlib was written by Jean-loup Gailly and Mark Adler and is an abstraction of the DEFLATE compression algorithm used in their gzip file compression program. zlib is also ...

compression (specifically, the compress2 function), typically resulting in a file size reduction for TrueType files of over 40%. Since OpenType CFF files (with PostScript glyph outlines) are already compressed, their reduction is typically smaller.

Vendor support

Each version of the format has received the backing of many font vendors, also known as

type foundries A type foundry is a company that designs or distributes typefaces. Before digital typography, type foundries manufactured and sold metal and wood typefaces for hand typesetting, and matrices for line-casting machines like the Linotype and Mono ...

, and has been supported by all major browsers: *

Firefox Mozilla Firefox, or simply Firefox, is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary, the Mozilla Corporation. It uses the Gecko rendering engine to display web pages, which implements current ...

since version 3.6 * Google Chrome since version 6.0 *

Internet Explorer Internet Explorer (formerly Microsoft Internet Explorer and Windows Internet Explorer, commonly abbreviated IE or MSIE) is a series of graphical web browsers developed by Microsoft which was used in the Windows line of operating systems ( ...

since version 9 *

Konqueror Konqueror is a free and open-source web browser and file manager that provides web access and file-viewer functionality for file systems (such as local files, files on a remote FTP server and files in a disk image). It forms a core part of t ...

since KDE 4.4.1 *

Microsoft Edge Microsoft Edge is a proprietary, cross-platform web browser created by Microsoft. It was first released in 2015 as part of Windows 10 and Xbox One and later ported to other platforms as a fork of Google's Chromium open-source project: Android ...

Opera Opera is a form of theatre in which music is a fundamental component and dramatic roles are taken by singers. Such a "work" (the literal translation of the Italian word "opera") is typically a collaboration between a composer and a libr ...

since version 11.10 ( Presto 2.7.81) * Safari 5.1 * other WebKit-based browsers since WebKit build 528 WOFF 2.0, based on the

compression algorithm and other improvements over WOFF 1.0 giving more than 30% reduction in file size, is supported in * Google Chrome (since version 36), * Edge (since version 14), * Opera (since version 26), * Firefox (since version 35) * Safari (since version 10). Some browsers enforce a same-origin policy, preventing WOFF fonts from being used across different domains. This restriction is part of the

CSS 3 Cascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language such as HTML or XML (including XML dialects such as SVG, MathML or XHTML). CSS is a cornerstone technol ...

Fonts module, where it applies to all font formats and can be overridden by the server providing the font. Some servers may require the manual addition of WOFF's MIME type to serve the files correctly. Since February 2017, the proper MIME type is font/woff for WOFF 1.0 and font/woff2 for WOFF 2.0. Prior to February 2017, the standard MIME type for WOFF 1.0 was application/font-woff, and some applications may still use the old type, though it is now deprecated.

References

External links

Current specification of the WOFF 1.0 file format
at the

's website
Current specification of the WOFF 2.0 file format
at the

's website {{DEFAULTSORT:Web Typography Digital typography Font formats Typesetting World Wide Web Consortium standards Computer-related introductions in 2009

Standardization

Specification

Vendor support

See also

References

External links