WOFF, short for Web Open Font Format, is a format designed in 2009 for fonts used on the web, which became a W3C Recommendation in 2012. It takes a TTF or OTF font, compresses it and can add metadata such as the license, without changing the design of the letters.
Where to see it
WOFF is recognizable by the .woff extension of the files called by a website's CSS @font-face rule. Today it mainly serves as a fallback for older browsers that do not support WOFF2.
Why this detail matters
WOFF was a decisive step for typography on the web:
- By compressing font files, it made it possible to load custom fonts without weighing pages down too much;
- Its license metadata reassured foundries, which could more easily allow their fonts to be used on the web;
- It has now been superseded by the lighter WOFF2: it is only added as a complement, for browsers that cannot read WOFF2.
Related term
WOFF2 is the second version of this format; thanks to better compression, it produces files about 30% smaller.