WOFF vs WOFF2: Complete Guide to Web Font Format Differences
Understanding Web Open Font Format compression, browser support, performance characteristics, and which format to choose for optimal web typography
In Simple Terms
WOFF2 is 30% smaller than WOFF due to Brotli compression (vs zlib). Both have excellent browser support.Use WOFF2 as primary, WOFF as fallback only if supporting pre-2014 browsers. Most sites can drop WOFF entirely.Implementation: List WOFF2 first in @font-face src. WOFF2 has 97%+ support, WOFF adds coverage for IE9-11 only.
In this article
WOFF (Web Open Font Format) and WOFF2 are compression formats specifically designed for delivering fonts on the web. While both serve the same purpose, WOFF2 offers significantly better compression through its use of the Brotli algorithm, achieving 30% better compression than WOFF's gzip-based approach.
For modern web projects, WOFF2 is the recommended primary format with WOFF serving as a fallback for legacy browsers. WOFF2 enjoys 97%+ browser support and delivers measurable performance improvements through smaller file sizes and faster page loads.
WOFF vs WOFF2: Format Overview
WOFF (Web Open Font Format 1.0)
Released in 2009 and standardized by W3C in 2012, WOFF uses gzip compression to reduce font file sizes by 40-50% compared to uncompressed TTF/OTF fonts.
- • Uses zlib/gzip (DEFLATE) compression
- • Compresses each font table independently
- • Universal browser support (99.8%)
- • Fast compression and decompression
- • File extension: .woff
WOFF2 (Web Open Font Format 2.0)
Released in 2014 by Google and standardized in 2018, WOFF2 uses Brotli compression and achieves 60-70% reduction from original fonts—30% better than WOFF.
- • Uses Brotli compression algorithm
- • Preprocesses font data for better compression
- • Compresses entire font as single stream
- • 97%+ browser support (all modern browsers)
- • File extension: .woff2
Compression and Performance
Real-World File Size Comparison
| Font | Original TTF/OTF | WOFF | WOFF2 |
|---|---|---|---|
| Roboto Regular | 168 KB | 85 KB | 53 KB |
| Open Sans Bold | 224 KB | 112 KB | 71 KB |
| 4-Font Family | 612 KB | 306 KB | 188 KB |
WOFF2 consistently delivers 30-40% smaller files than WOFF, translating to faster page loads and reduced bandwidth costs.
Performance Impact
For a typical website using 4 font files (383KB WOFF vs 241KB WOFF2):
- • 37% smaller payload: 142KB saved per page load
- • 0.6 seconds faster on typical 4G mobile connection
- • Improved Core Web Vitals: Better LCP and FCP scores
- • Reduced bandwidth costs for high-traffic sites
Browser Support and Compatibility
| Browser | WOFF | WOFF2 |
|---|---|---|
| Chrome | Since 2010 | Since 2014 |
| Firefox | Since 2010 | Since 2015 |
| Safari | Since 2011 | Since 2016 |
| Edge | Since 2015 | Since 2016 |
| IE 11 | ✓ Yes | ✗ No |
Support Summary
- • WOFF: 99.8% global browser support
- • WOFF2: 97.5% global browser support
- • Only legacy browsers (IE11, old Safari/Android) lack WOFF2
- • Recommended: Use WOFF2 primary with WOFF fallback
Implementation Best Practices
Optimal @font-face Declaration
@font-face {
font-family: 'Roboto';
src: url('/fonts/roboto-regular.woff2') format('woff2'),
url('/fonts/roboto-regular.woff') format('woff');
font-weight: 400;
font-style: normal;
font-display: swap;
}List WOFF2 first—browsers use the first supported format. Modern browsers (97.5%) download WOFF2 and stop. Legacy browsers skip to WOFF fallback.
Font Preloading
<link rel="preload"
href="/fonts/roboto-regular.woff2"
as="font"
type="font/woff2"
crossorigin>Preload critical fonts to start downloads before CSS is parsed. Only preload 1-2 fonts used above-the-fold.
Implementation Checklist
- Convert fonts to WOFF2 and WOFF formats
- Write @font-face with WOFF2 listed first
- Add font-display property (swap or optional)
- Preload critical fonts in HTML head
- Set proper cache headers (1 year expiry)
- Test with WebPageTest and Lighthouse
When to Use Each Format
Use WOFF2 as Primary Format
WOFF2 should be your primary web font format for all modern projects:
- • Modern websites and web applications
- • Mobile-first projects (where file size matters most)
- • Performance-critical sites (e-commerce, news)
- • International sites serving users on limited bandwidth
- • Any project targeting browsers from 2016+
Include WOFF as Fallback When
- • You must support IE11 or old Safari/iOS versions
- • Enterprise environments with legacy browser requirements
- • Government or accessibility-focused sites needing maximum compatibility
- • You're uncertain about your audience's browser demographics
WOFF2-Only Strategy
Consider using only WOFF2 (no WOFF fallback) when:
- • Your analytics show less than 0.5% IE11 usage
- • You're building a modern web app for current browsers
- • Mobile-first project where iOS 10+ and Android 5+ are minimum
- • Simpler deployment is preferred and legacy support isn't required
The Bottom Line: WOFF2 for Modern Web
WOFF2 delivers 30-40% better compression than WOFF with excellent browser support (97%+). Use WOFF2 as your primary format with WOFF as fallback for legacy browsers. This strategy provides optimal performance for modern users while maintaining compatibility.
For new projects targeting current browsers, WOFF2-only is increasingly viable and simplifies deployment.
Written & Verified by
Sarah Mitchell
Product Designer, Font Specialist
WOFF vs WOFF2 FAQs
Common questions answered about this font format comparison