font/woff WOFF Common

What it's for

font/woff identifies WOFF (Web Open Font Format) files — the original web-optimized font format, designed specifically to compress and package font data for efficient web delivery, predating and superseded by WOFF2's improved compression. WOFF was itself a significant step forward when introduced (compared to serving raw TTF/OTF directly), and while WOFF2 is now the clear default for new web font delivery, WOFF retains real practical value as a fallback for the small remaining share of browsers/contexts that don't support WOFF2.

Format & syntax

Content-Type: font/woff

Referenced in CSS via @font-face, typically listed after WOFF2 as a fallback:

@font-face {
  font-family: "MyFont";
  src: url("myfont.woff2") format("woff2"),
       url("myfont.woff") format("woff");
}

No parameters. WOFF wraps font outline data (originally from a TTF or OTF source) with its own compression and metadata structure, similar in concept to WOFF2 but using an earlier, somewhat less efficient compression approach.

How it's used in practice

• Fallback in @font-face declarations — the primary remaining use case: listed as a fallback source after WOFF2 in @font-face src declarations, covering the narrow remaining gap of browsers/contexts without WOFF2 support.
• Legacy web projects predating WOFF2 adoption — some older codebases or established font-loading setups still primarily use WOFF (without a WOFF2 addition), reflecting when the project was originally built rather than current best practice.
• Font hosting services' broader compatibility coverage — third-party font hosting/delivery services commonly serve both WOFF2 and WOFF automatically as part of their format-negotiation logic, abstracting this fallback handling away from the developer entirely.

Common mistakes & gotchas

• Using WOFF as the primary/only web font format for new projects — given how broad WOFF2 support has become among modern browsers, defaulting to WOFF alone (without WOFF2) for a new project means serving unnecessarily larger font files than needed — WOFF2 should be the primary format, with WOFF only as an additional fallback if truly needed.
• Not knowing whether a WOFF fallback is actually still necessary — depending on your project's specific browser support requirements, a WOFF fallback alongside WOFF2 may add unnecessary complexity/file weight if your target audience's browsers already universally support WOFF2 — worth evaluating against your actual analytics rather than including it reflexively.
• Confusing WOFF and WOFF2 as interchangeable in performance terms — while conceptually similar (both are compressed web font wrapper formats), WOFF2's compression is meaningfully better, so treating them as roughly equivalent in file size expectations is a common but incorrect assumption.
• Manually converting fonts to WOFF without also generating WOFF2 — font conversion workflows that only produce WOFF (perhaps following outdated documentation/tutorials) miss out on WOFF2's better compression for the primary format most visitors will actually receive.

Comparison & FAQ

Do I still need to include a WOFF fallback alongside WOFF2?

It depends on your specific browser support requirements — WOFF2 support is broad among modern browsers, so many projects targeting only current browsers can skip the WOFF fallback entirely; check your actual traffic's browser distribution if you're unsure.

Is WOFF meaningfully different from WOFF2 in compression?

Yes — WOFF2 achieves meaningfully better compression than WOFF for the same underlying font, which is exactly why WOFF2 became the recommended default and WOFF was relegated to fallback status.

Should I generate WOFF files for a brand new web project?

WOFF2 should be your primary format; only add a WOFF fallback if you have a specific, verified need to support older browsers that don't support WOFF2 — otherwise you're adding unnecessary file weight without benefit.

Can I convert an existing WOFF font to WOFF2 for better compression?

Yes, font conversion tools can typically convert between these formats (often starting from an original TTF/OTF source is cleanest), and doing so to get WOFF2's better compression as your primary delivery format is generally a worthwhile improvement.