What is .woff?
WOFF (Web Open Font Format) and its successor WOFF2 are font formats specifically designed for use on web pages. They are essentially OpenType or TrueType fonts with compression and additional metadata, enabling faster loading times and bandwidth savings.
This quick guide explains when to use .woff files, how to open them on any device, and how to share them instantly with FileXhost.
When to use .woff files
- You want to use custom fonts on your website using CSS `@font-face`.
- You need to optimize font loading speed (WOFF2 offers roughly 30% better compression than WOFF).
- You need broad browser compatibility for web typography.
How to open .woff files
WOFF files are not meant to be opened directly by users. They are loaded by web browsers to render text. You can view them by inspecting a webpage or using font viewer tools.
Algorithm details
WOFF is a wrapper around TTF/OTF fonts with table-based compression. WOFF2 improves on this by using the Brotli compression algorithm and transforming font data to be more compressible, resulting in significantly smaller file sizes.
Browser & platform support
- WOFF: Supported by all modern browsers and IE9+.
- WOFF2: Supported by all modern browsers (Chrome, Firefox, Safari, Edge).
Format comparison
| Feature | Details |
|---|---|
| Compression | WOFF2 is the most efficient, followed by WOFF. TTF/OTF are uncompressed and larger. |
| Usage | Designed strictly for the web. Not typically used for desktop installation (though possible). |
| Metadata | Supports licensing data within the file structure. |
How to create woff files
- Converters: Tools like FontSquirrel or Transfonter to convert TTF/OTF to WOFF/WOFF2.
- CLI: `sfnt2woff` or `woff2_compress` tools.
- Google Fonts: Automatically serves WOFF2 to capable browsers.
How to convert woff files
- Online Converters: Convert WOFF to TTF for desktop use.
- FileXhost: Host font files for your website.
Advantages & disadvantages
Advantages
- Standard for web typography
- Excellent compression (especially WOFF2)
- Widely supported by browsers
- Protects font foundries (harder to pirate than raw TTF)
Disadvantages
- Not natively supported by most desktop OS image viewers (needs conversion to install)
- WOFF2 requires modern browsers (though fallback is easy)
Tools & software
Generators
FontSquirrel Webfont Generator, Transfonter
Design
Figma, Sketch (via plugins)
Development
CSS (@font-face rules)
Frequently asked questions
Should I use WOFF or WOFF2?
Use WOFF2 for modern browsers and provide WOFF as a fallback for older ones in your CSS.
Can I install WOFF on Windows/Mac?
Generally no. You usually need the original TTF or OTF file to install a font on your operating system, though some tools can convert WOFF back to TTF.
How do I use it in CSS?
Use the `@font-face` rule: `src: url('font.woff2') format('woff2'), url('font.woff') format('woff');`
Technical specs
- File type
- Web
- Extension
- .woff
- MIME type
- font/woff, font/woff2, application/font-woff
- Compression
- Uncompressed
- Max file size on FileXhost
- Typically very small (10KB - 100KB). Up to 25 MB per file on free plans.
Share .woff files instantly
Upload your .woff file to FileXhost to get a clean, shareable URL in seconds. View the file in a modern browser, protect access with optional settings, and let others download it without any confusing ads or cluttered file pages.
Upload .woff file