The web open font format (WOFF)

WOFF stands for Web Open Font Format. It packages font data in a compressed container made for delivery in web pages.

The important practical benefit is size. WOFF uses zlib compression around the original font data, reducing transfer size without changing the outlines or lowering their quality.

WOFF can carry metadata and private data alongside font tables. It is a container rather than a new font-drawing system: the underlying data normally comes from a TrueType or OpenType font.

That also means language and character support depend on the font inside the file, not on WOFF itself. Packaging a font as WOFF does not add glyphs that were missing from the source.

By 2020, WOFF had broad browser support, including Chrome, Firefox, Safari, and Internet Explorer. WOFF2 offered better compression in newer browsers, so a common setup was to serve WOFF2 first and keep WOFF as a fallback.

For a modern site, I would start with WOFF2. WOFF remains useful when you need to support older browsers, and it is still much better suited to web delivery than shipping an uncompressed desktop font.