.woff2 File Extension

Learn what a .woff2 file is, how to open and use WOFF2 web fonts, how Poly supports them, and when to choose WOFF, TTF, or OTF instead.

File extension details for .woff2

Storage Only
File typeWeb Open Font Format 2.0 font
MIME type
EncodingBinary WOFF2 container with transformed font tables and Brotli compression
Operating systemsWindows, macOS, Linux, iOS, Android
Opens withWeb browsers, FontForge, fontTools, WOFF2 utilities
Poly supportYes. Poly stores, syncs, shares, versions, and downloads WOFF2 fonts.
Indexed by PolyPartial. Poly indexes the filename and ordinary file properties, not font tables or glyphs.
Preview in PolyNo. Download the file or load it in a web page to preview the typeface.
Poly agentPartial. The agent can use basic file identity and properties, but cannot inspect the font's contents.

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

Renaming a .ttf, .otf, or WOFF file to .woff2 does not compress or convert it. Use a font-aware WOFF2 encoder.

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 stores, syncs, shares, versions, and downloads WOFF2 files, and makes them searchable by filename and ordinary file properties. Poly does not currently render a type specimen, index family names or character coverage, or expose glyphs and font tables to the agent.

Download the file and open it with a trusted font tool or test page when you need to check its appearance, variation axes, OpenType features, language coverage, or embedded licensing information.

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

FormatBest fit
.woff2Efficient delivery to modern web browsers
WOFFFallback for older browsers required by a project
.ttfInstallable or editable fonts with TrueType outlines
.otfOpenType authoring, exchange, or desktop installation

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.

Footnotes

  1. Internet Assigned Numbers Authority. font/woff2 Media Type Registration.
  2. World Wide Web Consortium. WOFF File Format 2.0. W3C Recommendation. 2
  3. MDN Web Docs. @font-face.
  4. World Wide Web Consortium. WOFF File Format 2.0 Publication History.
  5. Lilley, C. RFC 8081: The font Top-Level Media Type. Internet Engineering Task Force, February 2017.
  6. Lilley, C. WOFF 2.0, the Inside Scoop. World Wide Web Consortium, March 1, 2018.
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