EOT vs PFB: Complete Format Comparison
Comprehensive comparison of EOT and PFB formats covering failed web font versus obsolete PostScript, two eras of proprietary lock-in, and why both are completely obsolete
In Simple Terms
Both are completely obsolete. EOT (IE-only, 0% support since IE11 retired 2022). PFB (PostScript Type 1, deprecated, Adobe ended support 2023).EOT failed due to IE-only lock-in. PFB succeeded but was replaced by superior OpenType. Both represent failed proprietary approaches.Convert both to modern formats: EOT → delete, use WOFF2 for web. PFB → OTF for desktop. Never use EOT or PFB in new projects.
In this article
EOT (Embedded OpenType) and PFB (PostScript Font Binary) represent two proprietary font formats from different eras that both failed to achieve universal adoption, with EOT being Microsoft's IE-only web font attempt (1997-2022) and PFB being Adobe's PostScript Type 1 desktop format that dominated professional publishing (1984-2005) before being replaced by OpenType. EOT, created exclusively by Microsoft in 1997 for Internet Explorer 4, used MicroType Express compression achieving ~40-50% size reduction with DRM features, but remained locked to IE throughout its existence—other browsers refused to implement it, and IE11's retirement in June 2022 dropped EOT support to 0%. PFB, created by Adobe in 1984 as part of the PostScript specification, stores Type 1 font data as binary-encoded cubic Bézier curves in a two-file system (PFB for outlines + PFM/AFM for metrics), designed for PostScript printers and professional typesetting until OpenType unified the industry in the mid-2000s.
The critical distinction is era and purpose: EOT attempted web font delivery but failed due to single-vendor lock-in (web format, 1997-2022, 0% support now), while PFB succeeded as desktop publishing standard but was replaced by OpenType (desktop format, 1984-2005, deprecated now). Both demonstrate the problems of proprietary formats—EOT failed because other browsers rejected Microsoft's approach, and PFB succeeded temporarily but was eventually replaced by the open OpenType standard that unified PostScript and TrueType technologies. As of 2025, both have 0% web support and declining desktop support, replaced by WOFF2/WOFF for web and OTF/TTF for desktop.
This guide compares EOT and PFB to understand how proprietary formats from different eras both became obsolete. You'll learn the technical specifications showing EOT's IE-only DRM versus PFB's PostScript printing heritage, platform compatibility demonstrating both formats' limitations, historical context explaining their rise and fall across three decades, complete migration paths from both legacy formats to modern standards, and definitive recommendations to use WOFF2/WOFF for web and OTF for desktop. Whether maintaining legacy documents or understanding font format history, this guide provides essential knowledge about two proprietary formats that ultimately failed to survive industry evolution.
Format Overview
EOT (Embedded OpenType)
History and Purpose:
- • Created by Microsoft exclusively (1997, IE4)
- • Proprietary web font with DRM features
- • Never adopted by Chrome, Firefox, Safari
- • IE11 retired June 2022
- • Obsolete: 0% browser support
Technical Characteristics:
- • MicroType Express compression (~40-50%)
- • DRM: URL binding, root strings
- • File size: ~80 KB
- • Extension: .eot
Current Status (2025):
- • Zero browser support
- • Failed: single-vendor lock-in
- • Use case: None (remove immediately)
PFB (PostScript Font Binary)
History and Purpose:
- • Created by Adobe (1984) for PostScript
- • Dominated professional publishing 1984-2005
- • Designed for PostScript printers/RIPs
- • Replaced by OpenType (OTF) mid-2000s
- • Obsolete: foundries stopped distribution
Technical Characteristics:
- • PostScript Type 1, cubic Bézier curves
- • Two-file system: PFB + PFM/AFM
- • File size: ~40-120 KB (outline only)
- • Extension: .pfb (binary) or .pfa (ASCII)
Current Status (2025):
- • Obsolete desktop format
- • Replaced by OpenType
- • Use case: Legacy documents only
Two Eras, Same Result: Obsolete
- EOT (1997-2022): Failed web font, IE-only, DRM complexity, 0% support
- PFB (1984-2005): Successful desktop font, replaced by OpenType, deprecated
- Common fate: Both obsolete, both proprietary, both replaced by open standards
- Modern replacements: WOFF2/WOFF (web), OTF/TTF (desktop)
Technical Differences
Comprehensive Comparison
| Feature | EOT | PFB |
|---|---|---|
| Creator | Microsoft (proprietary) | Adobe (proprietary) |
| Era | 1997-2022 (web) | 1984-2005 (desktop) |
| Purpose | Web font delivery | Desktop/print PostScript |
| Platform | IE only (Windows) | Desktop (Win/Mac) |
| Compression | MicroType Express (~40-50%) | None |
| File Size | ~80 KB | ~80 KB (similar) |
| DRM | Yes (URL binding) | None |
| File Structure | Single file | Two files (PFB+PFM) |
| Status | Obsolete (0%) | Obsolete |
EOT Proprietary Lock-In
- IE exclusive: Microsoft only, other browsers rejected
- DRM backfire: URL binding complexity hurt adoption
- Never universal: 25 years and never got beyond IE
- Complete failure: 0% support when IE retired
PFB Proprietary Success Then Obsolescence
- Initial success: Dominated professional publishing 20 years
- PostScript dominance: Industry standard for print
- OpenType replaced: Unified format better than proprietary
- Industry transition: Foundries stopped distributing by mid-2000s
Platform Compatibility
Platform Support Matrix
| Platform | EOT | PFB |
|---|---|---|
| Web Browsers (All) | ✗ (0%) | ✗ |
| Windows Desktop | ✗ | ~ |
| macOS Desktop | ✗ | ~ |
| Linux Desktop | ✗ | ~ |
| Mobile | ✗ | ✗ |
~ = Limited/deprecated desktop support
✗ = No support
Historical Context
Timeline: Three Decades
- 1984: Adobe creates PostScript and Type 1 (PFB)
- 1984-1996: PFB dominates professional publishing
- 1996: Adobe + Microsoft create OpenType to unify
- 1997: Microsoft creates EOT for IE4 (web fonts)
- 1997-2009: EOT remains IE-exclusive
- 2000s: Industry transitions from PFB to OTF
- 2009: WOFF created as open web font standard
- 2012: WOFF becomes W3C standard, EOT obsolescence begins
- 2022: IE11 retired, EOT drops to 0%
- 2025: Both EOT and PFB completely obsolete
Lessons: Why Proprietary Formats Eventually Fail
- • Single-vendor control: Prevents universal adoption (EOT)
- • Even success temporary: PFB dominated 20 years but still replaced
- • Open standards win: OpenType unified, WOFF succeeded
- • Industry consensus matters: Collaboration beats proprietary
Migration Strategy
Complete Migration Path
From EOT (Web):
- Remove all EOT references from CSS
- Delete .eot files from server
- Obtain OTF/TTF source fonts
- Convert to WOFF2 + WOFF using FontTools
- Implement modern @font-face
- Test in all browsers
From PFB (Desktop):
- Identify PFB fonts in archives
- Convert PFB → OTF (CFF) using FontForge/AFDKO
- Install OTF for desktop use
- Convert OTF → WOFF2 + WOFF for web
- Archive PFB for legacy documents
Modern Implementation
/* Modern web font stack (2025) */
@font-face {
font-family: 'MyFont';
src: url('/fonts/font.woff2') format('woff2'),
url('/fonts/font.woff') format('woff');
font-display: swap;
}
/* No EOT: 0% support, obsolete */
/* No PFB: Desktop only, obsolete */
/* WOFF2: 97%+, 53 KB (primary) */
/* WOFF: 99%+, 90 KB (fallback) */Modern Recommendations
Use Modern Standards:
- • Web: WOFF2 (primary) + WOFF (fallback), 99%+ coverage
- • Desktop: OTF or TTF, universal compatibility
- • Open standards: W3C specifications, industry consensus
Never Use EOT or PFB:
- • EOT: 0% support, completely obsolete
- • PFB: Deprecated, replaced by OTF
- • Action: Remove/convert immediately
Migration Checklist
- ☐ Remove all EOT references from CSS
- ☐ Delete .eot files from server
- ☐ Convert PFB to OTF (CFF) for desktop
- ☐ Convert OTF to WOFF2 + WOFF for web
- ☐ Test fonts in all target platforms
- ☐ Archive originals for legacy documents
- ☐ Document font sources and licenses
Summary: EOT vs PFB
EOT and PFB represent proprietary formats from different eras that both became obsolete. EOT (Microsoft 1997) failed as IE-only web font with 0% support since IE11 retired (2022). PFB (Adobe 1984) succeeded as desktop publishing standard but was replaced by OpenType in mid-2000s. Both demonstrate proprietary format limitations—EOT failed due to single-vendor lock-in, PFB succeeded temporarily but eventually replaced by open standard. Use WOFF2/WOFF for web (99%+ coverage) and OTF/TTF for desktop (universal). Remove all EOT references immediately. Convert PFB to OTF for desktop use.
Written & Verified by
Sarah Mitchell
Product Designer, Font Specialist
EOT vs PFB FAQs
Common questions answered about this font format comparison