WOFF (web font)
Also known as: .woff file, Web Open Font Format, web font file
WOFF (Web Open Font Format) is a compressed font format made for the web. It wraps a TrueType or OpenType font with compression and metadata so it downloads faster on a webpage, which is why sites serve WOFF rather than raw TTF or OTF.
- Compressed web-delivery wrapper around TTF/OTF fonts
- Loaded by browsers via CSS, no install needed
- Superseded by the smaller WOFF2
Fonts built for the browser
A WOFF file takes an existing TTF or OTF outline font and compresses it, then adds metadata, specifically so it can be delivered efficiently over the web. The result renders the same as the original font but transfers as a smaller download.
Browsers load WOFF through CSS, which is how custom typefaces appear on websites without the visitor installing anything.
WOFF vs WOFF2
WOFF was the first web-font standard; WOFF2 is its successor and compresses more aggressively, producing smaller files and faster page loads. Modern browsers support both, and sites usually offer WOFF2 first with WOFF as a fallback.
These files are small and used by websites rather than stored in your photo or document library, so they are about page performance, not device storage.