A WOFF2 file is a web font file created in the WOFF (Web Open Font Format) 2.0 format, an open format used to deliver webpage fonts on the fly. It is saved as a compressed container that supports TrueType (.TTF) and OpenType (.OTF) fonts. WOFF2 files also support font licensing metadata.
The WOFF 2.0 format is similar to the WOFF 1.0 format but features improved compression in order to decrease network bandwidth use. The format is based on the Brotli compression algorithm, which is an open source data compression library used to increase the speed of web browsing. WOFF2 files are roughly 30% smaller than .WOFF files.
WOFF2 files allow web developers to use custom fonts rather than the standard web fonts. Many browsers support the WOFF format, including Chrome (beginning in version 36), Edge (beginning in version 14), Firefox (beginning in version 35), Safari (beginning in version 10), and Opera (beginning in version 26).
NOTE: WOFF2 files are referenced within CSS files using the @font-face rule.