.woff2 File Extension

What kind of file is a .woff2?

A .woff2 file is a Web Open Font Format 2.0 package made for delivering fonts to web browsers. It uses the registered font/woff2 MIME type and usually contains an sfnt-based TrueType or OpenType font. WOFF2 preserves the glyphs, character mappings, metrics, layout features, and other supported tables in a compact transport format.¹²

WOFF2 is a container, not a new outline technology. Its first four bytes are 77 4F 46 32, which spell wOF2 in ASCII. A conforming reader also validates the header and table directory, since a .woff2 filename alone does not prove that the contents are a valid font.²

How do I open a .woff2 on my computer?

Current Chrome, Edge, Firefox, Opera, and Safari can load WOFF2 through CSS @font-face.³ The most reliable visual check is to reference the file from a small HTML and CSS specimen. Opening it directly may only download it.

Use FontForge, fontTools, or the reference WOFF2 utilities when you need to decode or inspect font tables. A .woff2 file is primarily a web resource and may not install directly in a desktop font manager. Keep browsers and font tools updated, and validate unfamiliar fonts before decoding or installing reconstructed output.

Poly support for .woff2

Poly previews WOFF2 fonts with a type specimen, shows face details, and lets you find files by filename or visual similarity. The details panel shows the family, format, weight, style, monospaced and variable-font status, face and glyph counts, and estimated language coverage. These fields are not full-text indexed.

The Poly agent can inspect the specimen image and a caption with the family, format, glyph count, and language coverage. Poly processes the first face of a collection and uses default variation settings, so the preview and agent view do not show other faces or alternate variable-font axis positions. Use a font editor or a web specimen when you need those details or want to inspect the underlying tables.

History of .woff2

The W3C WebFonts Working Group published its first WOFF2 draft in May 2014. WOFF2 became a W3C Recommendation on March 1, 2018.⁴ RFC 8081 had registered font/woff2 and the dedicated font media-type tree in February 2017.⁵

WOFF2 followed WOFF 1.0, replacing per-table Flate compression with font-aware table transforms and Brotli compression. In W3C's development datasets, WOFF2 averaged 27% smaller than WOFF for TrueType outlines and 13.5% smaller for CFF outlines. Results vary by font and encoder.⁶

Working with .woff2 and alternatives

Keep the licensed TTF or OTF source as the master, then generate WOFF2 delivery files from it. Subsetting can save more bandwidth by removing unused characters, but it can also break language coverage or shaping if required glyphs and layout tables are omitted. Test every needed language, weight, style, feature, and variable axis.

Conversion and compression do not grant permission to publish a font. Confirm that its license permits web embedding, modification, subsetting, and redistribution before deployment.