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TTF vs EOT: Complete Format Comparison

Comprehensive comparison of TrueType Font (TTF) and Embedded OpenType (EOT) formats covering compatibility, performance, and modern alternatives

TL;DR

In Simple Terms

EOT is completely obsolete with 0% browser support (IE11 retired June 2022). Never use EOT in new projects—remove all references.TTF is for desktop installation and font development. Use TTF for design apps and as source files, not for web delivery.For web: Convert TTF to WOFF2 (primary, 97%+ support) and WOFF (fallback). Skip EOT entirely—it's no longer needed for any browser.

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TrueType Font (TTF) and Embedded OpenType (EOT) represent two historically important font formats, though they serve different purposes and eras. TTF, developed by Apple in 1989 and later adopted by Microsoft, is a desktop font format designed for operating systems and applications. EOT, created by Microsoft in 1997, was specifically designed for web embedding to address Internet Explorer's requirements for font obfuscation and compression. While TTF remains relevant as a desktop format and conversion source, EOT is now obsolete—supported only by Internet Explorer 6-11, which Microsoft officially retired in 2022.

The fundamental difference between these formats lies in their intended use and technical implementation. TTF files are uncompressed, desktop-focused font files typically 150-300 KB containing complete glyph sets, hinting instructions, and OpenType features. EOT files are compressed, web-focused versions of TrueType or OpenType fonts with Microsoft's proprietary compression algorithm (MicroType Express), DRM protection, and subsetting capabilities, typically 40-60% smaller than their TTF counterparts. However, EOT's browser support limitation—only Internet Explorer—and the emergence of superior alternatives (WOFF, WOFF2) have rendered it obsolete for modern web development.

This comprehensive guide compares TTF and EOT across all relevant dimensions to help developers understand these formats and make informed decisions. You'll learn the technical specifications of each format, detailed compatibility matrices showing browser support over time, performance comparisons including file sizes and load times, appropriate use cases for each format in 2025, migration strategies from EOT to modern formats, and why WOFF2 has replaced both formats for web use. Whether maintaining legacy code or planning new projects, this guide provides the knowledge to handle font formats effectively.

Format Overview

TrueType Font (TTF)

History and Purpose:

  • • Developed by Apple in 1989, licensed to Microsoft in 1991
  • • Designed for desktop operating systems (Windows, macOS)
  • • Became standard for system fonts and applications
  • • Still widely used for desktop publishing and design work

Technical Characteristics:

  • • Uncompressed format with complete font data
  • • Quadratic Bézier curves for glyph outlines
  • • Includes hinting instructions for screen rendering
  • • Supports full Unicode character sets
  • • File extension: .ttf

Typical File Size:

150-300 KB for Latin fonts with full character set

Embedded OpenType (EOT)

History and Purpose:

  • • Created by Microsoft in 1997 for Internet Explorer 4.0
  • • Designed specifically for web font embedding
  • • Included DRM to address font licensing concerns
  • • Never adopted by other browsers (Chrome, Firefox, Safari)
  • • Obsolete format as of 2025

Technical Characteristics:

  • • Compressed with MicroType Express algorithm
  • • Includes URL binding for domain restrictions
  • • Supports font subsetting to reduce file size
  • • Root string embedding for basic DRM
  • • File extension: .eot

Typical File Size:

60-180 KB (40-60% smaller than TTF due to compression)

Critical Status Update (2025)

EOT is obsolete and should NOT be used in new projects:

  • • Internet Explorer 11 (only browser supporting EOT) retired June 2022
  • • No modern browser supports EOT format
  • • WOFF and WOFF2 have universal support (97%+ browsers)
  • • EOT conversion tools increasingly deprecated
  • • Remove EOT from legacy codebases during maintenance

Technical Differences

Side-by-Side Technical Comparison

FeatureTTFEOT
Primary UseDesktop OS, applicationsWeb (IE only)
CompressionNone (uncompressed)MicroType Express
File Size150-300 KB (baseline)60-180 KB (40-60% smaller)
DRM/ProtectionNoneURL binding, root string
SubsettingRequires external toolsBuilt-in support
Browser SupportAll (but not optimal for web)IE 6-11 only (obsolete)
StandardizationISO standardMicrosoft proprietary
Modern RelevanceDesktop use, conversion sourceObsolete (do not use)

Compression Technology

TTF Compression:

  • • No built-in compression
  • • Raw font data stored as-is
  • • Can be compressed with external tools (gzip) during HTTP transfer
  • • Results in larger file sizes compared to web-optimized formats

EOT Compression:

  • • MicroType Express compression algorithm
  • • Achieves 40-60% size reduction
  • • Proprietary to Microsoft, not documented publicly
  • • Less efficient than modern Brotli (used in WOFF2)

DRM and Protection Mechanisms

TTF Protection:

None. TTF files are completely unprotected and can be copied, modified, or redistributed. Protection relies entirely on licensing agreements.

EOT Protection:

  • • URL binding: Font tied to specific domain
  • • Root string: Embedded identifier for tracking
  • • Limited effectiveness: Basic obfuscation, not cryptographic protection
  • • Purpose: Address foundry concerns about web font piracy

Note: EOT's DRM did not prevent unauthorized use and became irrelevant as other browsers adopted non-DRM formats (WOFF).

Browser Compatibility

Browser Support Matrix

BrowserTTFEOTNotes
Chrome (All)✓✗Never supported EOT
Safari (All)✓✗Never supported EOT
Firefox (All)✓✗Never supported EOT
Edge (Modern)✓✗Chromium-based, no EOT
IE 6-8✗✓EOT only
IE 9-11✓✓Both supported

Current Reality (2025): IE11 retired June 2022. EOT support is 0% of active browsers.

The EOT Problem

EOT was created to serve Internet Explorer users, but its single-browser support created significant problems:

  • • Required maintaining separate EOT files alongside WOFF/TTF for other browsers
  • • Increased development complexity with conditional loading
  • • Never gained industry support - W3C standardized WOFF instead
  • • Microsoft eventually adopted WOFF in modern Edge browser
  • • IE11 retirement made EOT completely obsolete

Legacy @font-face Implementation

Historical example showing how developers had to support EOT:

/* Legacy approach (2010-2015) */
@font-face {
  font-family: 'MyFont';
  src: url('font.eot'); /* IE 6-8 */
  src: url('font.eot?#iefix') format('embedded-opentype'), /* IE 9-11 */
       url('font.woff2') format('woff2'), /* Modern browsers */
       url('font.woff') format('woff'), /* Older browsers */
       url('font.ttf') format('truetype'); /* Ancient browsers */
}

/* Modern approach (2025) */
@font-face {
  font-family: 'MyFont';
  src: url('font.woff2') format('woff2'),
       url('font.woff') format('woff');
  /* EOT removed - no longer needed */
}

Performance Comparison

File Size Comparison

Example: Roboto Regular font with full Latin character set

FormatFile Sizevs TTFLoad Time (4G)
TTF168 KBBaseline~1.1s
EOT80 KB52% smaller~0.53s
WOFF90 KB46% smaller~0.60s
WOFF253 KB68% smaller~0.35s

Key insight: WOFF2 is smaller than EOT (53 KB vs 80 KB) while supporting all modern browsers

Why WOFF2 Beats Both TTF and EOT

  • Better compression: Brotli algorithm (WOFF2) is superior to both uncompressed TTF and MicroType Express (EOT)
  • Universal support: 97%+ browsers vs EOT's 0% (IE retired)
  • Standard format: W3C recommended, industry-wide adoption
  • Best performance: 68% smaller than TTF, 34% smaller than EOT
  • Future-proof: Actively maintained, growing support

Use Cases and Recommendations

When to Use TTF (2025)

Appropriate Uses:

  • • Desktop applications: Installing fonts on Windows/macOS
  • • Design work: Using in Photoshop, Illustrator, InDesign
  • • Source for conversion: Converting TTF to WOFF2 for web
  • • Font development: Working with font editing tools

Avoid:

  • • Using TTF directly on websites (too large, not optimized)
  • • Web embedding without converting to WOFF2

When to Use EOT (2025)

DO NOT USE EOT:

  • • Format is completely obsolete
  • • Zero browser support (IE11 retired)
  • • WOFF2 is superior in every metric
  • • Increases complexity with no benefit

Only Exception:

If maintaining a legacy site that MUST support IE8-10 (extremely rare in 2025), keep EOT for those specific versions only. Even then, strongly recommend dropping IE support entirely.

Recommended Modern Stack (2025)

@font-face {
  font-family: 'MyFont';
  src: url('/fonts/font.woff2') format('woff2'),    /* Modern: 97%+ */
       url('/fonts/font.woff') format('woff');      /* Fallback: 99%+ */
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

/* No TTF needed (not optimized for web) */
/* No EOT needed (obsolete format) */

This two-format approach covers 99%+ of users with optimal performance

Migration from EOT to Modern Formats

Migration Strategy

  1. Audit current fonts: Identify all EOT files in project
  2. Obtain TTF/OTF sources: Get original font files (check licenses)
  3. Convert to WOFF2: Use FontTools or online converters
  4. Update @font-face: Remove EOT references, add WOFF2
  5. Test thoroughly: Verify fonts load in Chrome, Safari, Firefox
  6. Remove EOT files: Delete from server after testing

Before and After Example

Before (Legacy with EOT):

@font-face {
  font-family: 'MyFont';
  src: url('font.eot');
  src: url('font.eot?#iefix') format('embedded-opentype'),
       url('font.woff2') format('woff2'),
       url('font.woff') format('woff'),
       url('font.ttf') format('truetype');
}
/* Files: font.eot (80 KB) + font.woff2 (53 KB) + font.woff (90 KB) + font.ttf (168 KB) = 391 KB total */

After (Modern):

@font-face {
  font-family: 'MyFont';
  src: url('font.woff2') format('woff2'),
       url('font.woff') format('woff');
  font-display: swap;
}
/* Files: font.woff2 (53 KB) + font.woff (90 KB) = 143 KB total */
/* Result: 248 KB saved (63% reduction), same visual result */

Conversion Steps

If you have TTF sources:

# Convert TTF to WOFF2
fonttools ttLib.woff2 compress font.ttf
# Creates font.woff2

If you only have EOT:

Contact original font vendor for TTF/OTF files. EOT cannot be reliably converted back to TTF due to compression artifacts and potential subsetting.

Summary: TTF vs EOT

TTF and EOT served different purposes in font history: TTF as a desktop format (still relevant today) and EOT as a web format for Internet Explorer (now obsolete). EOT offered compression and DRM but suffered from single-browser support. With IE11 retirement in 2022, EOT support dropped to 0%, making it completely obsolete for web use.

Modern web development requires WOFF2 (primary) and WOFF (fallback) for 99%+ browser coverage. TTF remains relevant as a desktop format and conversion source. Remove EOT from legacy codebases—it adds complexity without benefit. WOFF2 is smaller (53 KB), faster, and universally supported compared to both TTF (168 KB) and EOT (80 KB). The web font landscape has evolved beyond both formats.

Sarah Mitchell

Written & Verified by

Sarah Mitchell

Product Designer, Font Specialist

TTF vs EOT FAQs

Common questions answered about this font format comparison