Starting in EdgeHTML 14.14316, Microsoft Edge supports WOFF 2.0 fonts — a new format that reduces the size of a font file by more than 30%, helping web pages load faster. This feature is available to preview via the Windows Insider Preview starting with build 14316, and is coming to stable builds with the Windows 10 Anniversary Update.
Over 60% of web pages use custom fonts, which make up 5.3% of the size of the average web page today. Modern sites are loading ever more data in the form of fonts, as the demand for custom fonts grows, and as site payloads in general trend upwards. Because of this trend, loading font files faster when rendering a page makes a huge difference in perceived performance; WOFF 2 provides a substantial improvement here.
WOFF 2 compresses fonts with Brotli to deliver more than 30% reduction in font file size over the earlier 2009-era W3C WOFF standard, which used zlib/compress2. WOFF 2 also uses font-specific compression based on the MicroType Express format that first used in web fonts in the EOT font format.
Using custom fonts is now easier than ever – WOFF 2 is widely interoperable, with support in EdgeHTML 14.14316 and later, in Firefox and Chrome, and coming soon in Safari. If you are using Google Fonts on your site, your work is already done – Microsoft Edge is already using WOFF 2 fonts from this service, with more services coming soon.
As always, we look forward to your feedback and comments!
– Frank Olivier, Principal Program Manager Lead, Microsoft Edge