WOFF vs TTF: Complete Font Format Comparison
Comprehensive comparison of WOFF and TTF formats covering compression, browser support, performance, and optimal use cases
In Simple Terms
TTF is uncompressed desktop format (168 KB), WOFF is compressed web format (85 KB). WOFF has 40% better compression with identical rendering.Use TTF for desktop apps and font installation. WOFF is specifically designed for web with built-in compression and metadata.For modern websites: Use WOFF2 (not WOFF) as primary format. WOFF2 is 30% smaller than WOFF with 97%+ browser support.
In this article
Choosing between WOFF and TTF font formats is a fundamental decision for web developers and designers. TTF (TrueType Font) is the traditional desktop font format that has been the industry standard since the late 1980s, while WOFF (Web Open Font Format) was specifically designed for web use in 2009. The choice between these formats directly impacts page load times, browser compatibility, file size, and overall web performance.
The key difference lies in their design philosophy: TTF was created for desktop operating systems where file size was less critical, while WOFF was engineered specifically for the web with built-in compression and metadata support. A typical TTF font file at 168 KB can be reduced to 85 KB in WOFF format through gzip compression, representing a 50% reduction in bandwidth and faster loading times.
This comprehensive comparison examines both formats across multiple dimensions including technical specifications, compression ratios, browser compatibility, performance characteristics, licensing considerations, and practical use cases. Understanding these differences enables you to make informed decisions about font deployment strategies for both web and desktop applications.
Format Overview
TTF (TrueType Font)
- Developed: 1980s by Apple and Microsoft
- Primary Use: Desktop operating systems (Windows, macOS, Linux)
- File Extension: .ttf
- Compression: None (uncompressed font data)
- Structure: Binary format with tables for glyph data, metrics, kerning, and hinting
- Advantages: Universal desktop support, simple structure, editable with font tools
- Disadvantages: Large file sizes, no built-in licensing protection, not optimized for web
WOFF (Web Open Font Format)
- Developed: 2009 by Mozilla, Opera, and Microsoft (W3C Recommendation in 2012)
- Primary Use: Web browsers and web applications
- File Extension: .woff
- Compression: Built-in gzip compression (zlib)
- Structure: Compressed TTF/OTF wrapped with metadata container
- Advantages: 40-50% smaller files, metadata support, licensing protection, web-optimized
- Disadvantages: Limited desktop application support, requires decompression
WOFF2 (Evolution)
Note: WOFF2, released in 2014, represents the next evolution with Brotli compression achieving 30% better compression than WOFF (68% smaller than TTF). WOFF2 is now the recommended format for modern web use with 97%+ browser support.
- • Uses Brotli compression algorithm
- • 30% smaller than WOFF, 68% smaller than TTF
- • Supported by all modern browsers (Chrome 36+, Firefox 39+, Safari 12+, Edge 14+)
Technical Differences
File Structure Comparison
| Aspect | TTF | WOFF |
|---|---|---|
| Container Format | Raw font tables | SFNT + WOFF header |
| Compression | None | Gzip (zlib) per-table |
| Metadata Block | Limited (name table) | Extended metadata support |
| Private Data | Not supported | Optional private block |
| Checksum | Per-table checksums | Full file checksum |
| Same-Origin | Not enforced | CORS headers respected |
Licensing and Protection
TTF Licensing:
- • No built-in license enforcement
- • Easily extracted and redistributed
- • Font embedding flags often ignored
- • Requires legal agreements only
- • Can be edited and modified easily
WOFF Licensing:
- • Metadata can include licensing info
- • Same-origin policy enforced by browsers
- • Private data block for vendor use
- • More difficult to extract source font
- • Industry standard for web licensing
Font Hinting Preservation
Both TTF and WOFF preserve TrueType hinting instructions completely:
- • TTF hinting instructions remain intact in WOFF conversion
- • Grid-fitting and anti-aliasing hints preserved
- • Low-resolution display optimization maintained
- • No quality loss during TTF to WOFF conversion
- • Glyph outlines and metrics identical after decompression
Compression and Performance
Real-World File Size Comparison
| Font Family | TTF Size | WOFF Size | Reduction |
|---|---|---|---|
| Roboto Regular | 168 KB | 85 KB | 49% |
| Open Sans Regular | 224 KB | 115 KB | 49% |
| Lato Bold | 186 KB | 92 KB | 51% |
| Montserrat SemiBold | 201 KB | 98 KB | 51% |
| Average | 195 KB | 98 KB | 50% |
Performance Impact Analysis
Load Time on 3G Connection (750 Kbps):
- • TTF (168 KB): ~1.8 seconds download time
- • WOFF (85 KB): ~0.9 seconds download time
- • Time saved: 0.9 seconds per font
- • For 4 font files: 3.6 seconds total savings
Load Time on 4G Connection (10 Mbps):
- • TTF (168 KB): ~135 ms download time
- • WOFF (85 KB): ~68 ms download time
- • Time saved: 67 ms per font
- • Multiplied across multiple fonts adds up significantly
Decompression Overhead:
- • WOFF decompression: 5-15 ms (modern browsers)
- • Negligible compared to download time savings
- • Browser caching eliminates repeat decompression
- • Net performance gain remains substantial
Core Web Vitals Impact
Using WOFF instead of TTF improves:
- • First Contentful Paint (FCP): 200-800ms faster with smaller font files
- • Largest Contentful Paint (LCP): Improved when text is LCP element
- • Total Blocking Time (TBT): Reduced download time = less blocking
- • Speed Index: Text renders faster with quicker font loads
- • Cumulative Layout Shift (CLS): Faster fonts reduce FOIT/FOUT duration
Browser Compatibility
Browser Support Matrix
| Browser | TTF Support | WOFF Support | WOFF2 Support |
|---|---|---|---|
| Chrome | 4.0+ (2010) | 5.0+ (2010) | 36.0+ (2014) |
| Firefox | 3.5+ (2009) | 3.6+ (2010) | 39.0+ (2015) |
| Safari | 3.1+ (2008) | 5.1+ (2011) | 12.0+ (2018) |
| Edge | All versions | All versions | 14.0+ (2016) |
| Internet Explorer | 9.0+ (2011) | 9.0+ (2011) | Not supported |
| Opera | 10.0+ (2009) | 11.1+ (2011) | 23.0+ (2014) |
Current global browser support: TTF (99%+), WOFF (99%+), WOFF2 (97%+)
Recommended Font Stack Strategy
Modern Approach (2025):
@font-face {
font-family: 'MyFont';
src: url('font.woff2') format('woff2'), /* Modern browsers (97%+) */
url('font.woff') format('woff'); /* Fallback for IE11 */
font-weight: 400;
font-style: normal;
font-display: swap;
}Note: TTF fallback no longer necessary. WOFF covers all browsers that don't support WOFF2 (primarily IE11 and old Safari).
Legacy Browser Support
If you need to support very old browsers (IE8 or older):
@font-face {
font-family: 'MyFont';
src: url('font.eot'); /* IE6-IE8 */
src: url('font.eot?#iefix') format('embedded-opentype'),
url('font.woff2') format('woff2'), /* Modern */
url('font.woff') format('woff'), /* IE9+, Modern */
url('font.ttf') format('truetype'); /* Ancient */
}Reality check: IE8 has under 0.01% market share globally. Supporting it is rarely justified in 2025.
Use Cases and Recommendations
When to Use WOFF/WOFF2
- ✓ Web applications and websites
- Primary use case - 50% smaller files
- Built-in licensing protection
- Universal browser support
- ✓ Email templates (HTML emails)
- Smaller file sizes critical for email performance
- Modern email clients support WOFF
- ✓ Progressive web apps (PWAs)
- Reduced bundle size improves offline performance
- Better Core Web Vitals scores
- ✓ E-learning platforms and web-based tools
- Faster loading on slower connections
- Better mobile performance
When to Use TTF
- ✓ Desktop applications
- Native apps (Windows, macOS, Linux)
- Required format for system font installation
- Electron apps may use either format
- ✓ Print and design work
- Adobe Creative Suite, Sketch, Figma (desktop)
- PDF embedding and print production
- Professional typography workflows
- ✓ Font editing and development
- FontForge, Glyphs, FontLab require TTF/OTF
- Source format for conversion to web formats
- Easier to modify and customize
- ✓ Mobile app development (iOS/Android)
- Native mobile apps use TTF/OTF formats
- Bundled with app package, size less critical
Decision Matrix
| Scenario | Best Format | Reason |
|---|---|---|
| Corporate website | WOFF2 + WOFF | Best performance, licensing |
| E-commerce site | WOFF2 + WOFF | Speed = conversions |
| Desktop software | TTF or OTF | OS requirement |
| Blog/Content site | WOFF2 + WOFF | SEO, Core Web Vitals |
| Hybrid/Electron app | WOFF2 (web view) | Smaller bundle size |
| Font distribution | TTF + OTF | Universal compatibility |
Conversion Methods
TTF to WOFF Conversion
Using Online Converter:
- Visit font-converters.com
- Upload your TTF file
- Select WOFF or WOFF2 as output format
- Click convert and download
- Quality identical to source - no data loss
Using FontTools (Python):
# Install FontTools pip install fonttools brotli # Convert TTF to WOFF ttx -f -o font.woff font.ttf # Convert TTF to WOFF2 (recommended) fonttools ttLib.woff2 compress font.ttf
Using woff2 Command Line:
# Install woff2 tools # macOS: brew install woff2 # Linux: sudo apt-get install woff2 # Compress to WOFF2 woff2_compress font.ttf # Output: font.woff2
WOFF to TTF Conversion
Using FontTools:
# Decompress WOFF to TTF ttx -f -o font.ttf font.woff # Decompress WOFF2 to TTF woff2_decompress font.woff2 # Output: font.ttf
Using Online Tools:
- • font-converters.com - Upload WOFF, download TTF
- • CloudConvert - Supports batch conversion
- • FontSquirrel Webfont Generator - Includes unpacking
Conversion Best Practices
- Always keep original TTF files: Use them as source for regenerating web fonts
- Validate before conversion: Check TTF quality to avoid propagating errors
- Test after conversion: Verify glyphs render correctly in target browsers
- Consider subsetting: Reduce file size further by removing unused characters
- Use WOFF2 when possible: 30% smaller than WOFF with 97%+ browser support
- Automate conversion: Use build tools for consistent results in production
Summary: WOFF vs TTF Decision Guide
For web use, WOFF and WOFF2 are unequivocally superior to TTF due to 50-68% file size reduction, built-in compression, licensing protection, and identical rendering quality. Modern web development should use WOFF2 as primary format with WOFF fallback for maximum browser coverage. TTF remains essential for desktop applications, print workflows, font development, and as source files for web font conversion.
The performance impact is substantial: converting a typical 4-font website from TTF to WOFF2 saves 450+ KB and improves load times by 2-3 seconds on mobile connections. This directly improves Core Web Vitals scores, SEO rankings, and user experience. Use TTF for desktop, WOFF2 for web - it's that simple.
Written & Verified by
Sarah Mitchell
Product Designer, Font Specialist
WOFF vs TTF FAQs
Common questions answered about this font format comparison