W3C's WOFF 2.0 significantly improves compression efficiency and lowers network bandwidth in fast decompression of font data

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WOFF 2.0 deployed in all major Web browsers, 70% of major websites now use Web Fonts


https://www.w3.org/ — 1 March 2018 — Web Open Font Format (WOFF) File Format 2.0, now a W3C Recommendation, significantly improves compression efficiency thus lowering use of network bandwidth, while allowing fast decompression of font data even on mobile devices.


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Web fonts are an important Web typography tool which allow Web designers to use fonts that are not installed on the viewer's computer. Web Open Font Format (WOFF) is a font packaging format designed to provide lightweight, easy-to-implement compression of font data with significantly better compression than previous techniques, suitable for use with CSS @font-face rules, that is deployed in all the major browsers.

Built on the success of WOFF 1.0

Published as a W3C Recommendation in 2012, WOFF 1.0 gave Web developers confidence to use WebFonts: browsers rapidly provided unequivocal, unified support for it, and the format received the backing of many of the main font foundries.

Designing it as a minimum viable product was instrumental in its success. Flate compression was already used by PNG and HTTP, resulting in fewer additions to the browsers.

Explosive growth of WebFonts usage

When WOFF 1.0 was started in 2010, a mere 1% of the the top ten thousand websites used WebFonts. By the time WOFF 2.0 was started in 2014, WebFont usage was up to 35% while today, it is up to 70%.

Improved compression that makes a difference

Custom font-specific preprocessing - based on MicroType Express by Monotype - removes redundancy and inefficiency from the TrueType or OpenType files. Then a newly-developed entropy coding scheme, Brotli, squeezes the font to the smallest size while not requiring excessive CPU or memory usage for decoding, even on lower-end mobile devices.

Backed up by a strong open source library

A good, open source, WOFF 2.0 encoder and decoder library was developed by Google in parallel with the specification. This allowed rapid experimentation, large scale testing, and a proven codebase which is now used by font foundries worldwide. The decoding portion is used by all the major browsers.

For more technical details on the specification as well as history, please read WOFF 2.0, the inside scoop, by Chris Lilley, on the W3C Blog.

About the World Wide Web Consortium

The mission of the World Wide Web Consortium (W3C) is to lead the Web to its full potential by creating technical standards and guidelines to ensure that the Web remains open, accessible, and interoperable for everyone around the globe. W3C develops well known specifications such as HTML5, CSS, and the Open Web Platform as well as work on security and privacy, all created in the open and provided for free and under the unique W3C Patent Policy. For its work to make online videos more accessible with captions and subtitles, W3C received a 2016 Emmy Award.

W3C's vision for "One Web" brings together thousands of dedicated technologists representing more than 400 Member organizations and dozens of industry sectors. W3C is jointly hosted by the MIT Computer Science and Artificial Intelligence Laboratory (MIT CSAIL) in the United States, the European Research Consortium for Informatics and Mathematics (ERCIM) headquartered in France, Keio University in Japan and Beihang University in China. For more information see https://www.w3.org/.

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