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Supported Formats
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Desktop Fonts
TrueType Font - universal desktop font format developed by Apple and Microsoft in the 1980s. Uses quadratic Bézier curves for glyph outlines. Excellent screen rendering with hinting technology. Works on all platforms (Windows, Mac, Linux). Supports Unicode with up to 65,536 glyphs. Standard desktop font format with maximum compatibility. Perfect for document embedding, desktop publishing, and cross-platform typography. Universal support in all operating systems and applications. Reliable choice for general-purpose font usage.
OpenType Font - modern font format jointly developed by Adobe and Microsoft (1996) extending TrueType. Uses cubic Bézier curves (PostScript outlines) allowing more complex glyph shapes. Supports advanced typography features (ligatures, alternate glyphs, contextual substitutions). Can contain up to 65,536 glyphs enabling comprehensive language support. Cross-platform compatibility (Windows, Mac, Linux). Industry standard for professional typography and multilingual documents. Perfect for print design, branding, and high-quality typography. Superior to TTF for complex scripts and advanced typographic features.
Mac Data Fork Font - legacy Macintosh font format storing TrueType/PostScript data in data fork. Used in Mac OS 9 and earlier. Phased out with Mac OS X transition to .ttf and .otf. Contains complete font data in single file (unlike resource fork fonts). Limited compatibility with modern systems. Convert to TTF or OTF for current macOS and cross-platform use. Historical format important for accessing old Mac fonts. Mainly encountered when migrating legacy Mac systems.
Compact Font Format - Adobe's space-efficient font outline format used within OpenType fonts. Stores glyph outlines using PostScript-based charstrings. More compact than TrueType outlines. Used in OTF fonts with PostScript outlines. Not standalone font file - embedded in OTF. Professional typography standard. Better compression than TTF outlines. Extract from OTF or work with complete OTF fonts.
CID-Keyed Font - Adobe font format for large character sets (Asian languages with thousands of characters). Character ID based system for efficient large font handling. Used in professional CJK (Chinese, Japanese, Korean) typography. Complex format requiring PostScript RIP support. Legacy format superseded by Unicode OpenType. Convert to modern OTF with Unicode mapping for compatibility. Important for accessing legacy Asian language fonts.
Spline Font Database - FontForge's native font format. Editable font source format storing complete font data including editing information. ASCII or binary format with full font metadata. Used in font design and development. Convert to TTF/OTF for deployable fonts. Perfect for font design workflow. Maintains complete font development history. FontForge is free open-source font editor.
Unified Font Object - open source font source format (XML-based directory structure). Developed by font tool creators for interoperability. Stores complete font design data in human-readable XML. Used by modern font editors (RoboFont, Glyphs, FontForge). Perfect for font development and version control. Industry standard for open font source files. Compile to TTF/OTF for distribution. Excellent for collaborative font design.
Web Formats
Web Open Font Format - font format specifically designed for web use (2009). Compressed TrueType/OpenType fonts reducing file size by ~40%. Supported by 99% of browsers (Chrome, Firefox, Safari, Edge). Includes metadata for licensing and font information. Perfect for website typography ensuring consistent rendering across devices. Industry standard for web fonts. Faster page loads than raw TTF/OTF. Essential for modern web design and custom typography. Recommended for broad web compatibility.
WOFF 2.0 - improved web font format (2014) with better compression using Brotli algorithm. 30% smaller than WOFF with faster decompression. Supported by all modern browsers (96%+ global coverage). Maintains WOFF's metadata and licensing features. Superior performance for web typography. Recommended format for modern websites. Falls back to WOFF for older browsers. Essential for optimizing website performance and reducing bandwidth. Default choice for contemporary web development.
Embedded OpenType - proprietary web font format developed by Microsoft for Internet Explorer. Compressed and subset fonts with DRM protection. Only supported by Internet Explorer (legacy browser). Obsolete format replaced by WOFF/WOFF2. Historically important for web fonts (1997-2010s). Still encountered in legacy websites. Not recommended for new projects. Convert to WOFF2/WOFF for modern browsers. Maintained only for backward compatibility with old IE versions.
SVG Font - vector-based font format embedded in SVG files. Defines glyphs as SVG paths allowing colors, gradients, and effects. Deprecated for web use in favor of WOFF. Limited browser support (only Safari supports SVG fonts). Larger file sizes than outline fonts. Mainly historical format. Useful for special effects and colored fonts. Modern alternative: OpenType-SVG. Not recommended for general use. Better options: WOFF2 with icon fonts or OpenType color fonts.
Specialized Formats
PostScript Font Binary - Adobe Type 1 binary format for professional printing (1984). Contains glyph outlines in PostScript language. Excellent print quality with precise curves. Requires corresponding PFM or AFM metrics file. Standard in professional publishing and printing industry. Limited to 256 glyphs (single-byte encoding). Being replaced by OpenType. Still used in legacy publishing workflows. Convert to OTF for modern compatibility while preserving PostScript quality.
PostScript Font ASCII - Adobe Type 1 ASCII variant of PFB format. Human-readable PostScript code defining font outlines. Used for font development and debugging. Less efficient than PFB binary format. Requires PFM or AFM metrics file. Same quality as PFB for printing. Legacy format for professional typography. Convert to OTF for modern systems. Primarily historical significance in desktop publishing evolution.
Printer Font Metrics - Windows metrics file for Type 1 PostScript fonts. Contains font measurements (character widths, kerning pairs, bounding boxes). Required companion to PFB/PFA for proper rendering on Windows. Text file format with font metrics data. Does not contain glyph outlines. Legacy format from Windows 3.1/95 era. Used with PFB for complete Type 1 font installation. Modern OpenType fonts include metrics internally. Convert Type 1 fonts to OTF to consolidate metrics and outlines.
Adobe Font Metrics - Adobe's metrics format for Type 1 PostScript fonts. Contains character widths, kerning pairs, ligatures, and bounding boxes. ASCII text format readable by humans and applications. Companion to PFB/PFA outline files. Used by font design tools and professional publishing software. Essential for proper font spacing and kerning. Legacy format with historical importance in digital typography. Modern fonts embed metrics in OTF format. Convert to OpenType for integrated metrics and outlines.
Binary Font File - generic binary font data format used by various font tools and editors. Contains raw font outline data without specific format wrapper. Used in font development and conversion pipelines. Requires specific tools to process. Not a standard end-user format. Intermediate format in font creation workflow. Convert to TTF or OTF for usable fonts. Primarily relevant in font design and development contexts.
Mac Suitcase Font - legacy Macintosh font container (Mac OS Classic) storing multiple fonts in one file. Contains TrueType or PostScript fonts in resource fork. Used with Font Suitcase format (.suit extension). Obsolete with Mac OS X migration. Poor compatibility with modern systems. Required Font/DA Mover for installation on old Macs. Extract individual fonts and convert to TTF/OTF for modern use. Important for recovering fonts from classic Mac archives and systems.
PostScript Font Program - Adobe PostScript Type 1 font in PostScript language format. Contains font outlines as PostScript code. Used for printer font downloads and font development. Human-readable but inefficient. Legacy format from desktop publishing era. Convert to OTF for modern usage. Historical importance in professional typography. Mainly encountered in old publishing workflows.
PageMaker 3 Font - legacy font format from Aldus PageMaker 3.0 (1980s desktop publishing). Proprietary format specific to early PageMaker versions. Obsolete format with no modern support. Important only for recovering old PageMaker documents. Convert to TTF/OTF if font data recoverable. Historical artifact from desktop publishing evolution. Better alternatives available for all uses.
Type 11 Font - variant of PostScript CID-Keyed font format. Used for complex fonts with large character sets. Legacy format for Asian language fonts. Limited modern support. Convert to Unicode OpenType for compatibility. Historical format in CJK font development. Modern alternatives handle large character sets better with Unicode.
Type 42 Font - PostScript font format wrapping TrueType outlines. Hybrid format combining PostScript wrapper with TrueType data. Used for downloading TrueType fonts to PostScript printers. Primarily printer-internal format. Limited end-user relevance. Convert underlying TrueType to TTF/OTF. Historical bridge between TrueType and PostScript worlds.
How to Convert Files
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Frequently Asked Questions
What is a CID-keyed font and why was it created for large character sets?
CID-keyed fonts use numerical identifiers instead of glyph names, allowing far larger character inventories than traditional Type 1 fonts.
This structure was essential for complex writing systems like Japanese, Chinese, and Korean.
It solved limitations that prevented classic Type 1 fonts from scaling to thousands of glyphs.
Why do CID fonts avoid traditional glyph naming conventions?
Named glyphs become impractical when a typeface contains tens of thousands of characters.
CID numbers provide a clean, stable index that simplifies font management.
This approach allows large scripts to be stored efficiently without naming conflicts.
Why are CID-keyed fonts commonly paired with CMap files?
CMap files map Unicode or legacy encodings to specific CID numbers.
They separate character encoding from glyph shape, allowing flexible text handling.
This modular system is vital for multilingual publishing and complex script engines.
Why do PDF documents frequently embed CID-keyed fonts?
CID fonts compress huge glyph sets effectively, which is crucial for East Asian PDF files.
Acrobat and many RIP systems interpret CID structures natively.
This ensures predictable rendering across all platforms and devices.
Why are CID-keyed fonts preferred for enterprise printing and publishing?
Their structure handles massive character sets without degrading performance.
Workflows like newspapers, large book projects, and government documents rely on CID consistency.
This reliability made CID a standard in professional print production.
Why do CID-keyed fonts integrate well with OpenType CFF?
OpenType can embed CID-keyed CFF data inside a single scalable container.
This allows compact, efficient storage of international font families.
It unifies PostScript-quality outlines with OpenType layout features.
Why do CID-keyed fonts avoid the 256-glyph limit of classic Type 1 fonts?
CID fonts store glyphs in indexed arrays rather than segmented encoding sets.
This makes them capable of supporting tens of thousands of characters in one file.
It eliminated a major constraint of legacy PostScript fonts.
Why do many CJK fonts rely on CID-keyed architecture for performance?
CID structures allow efficient memory mapping when loading thousands of glyphs into rasterizers.
Subroutines and shared components reduce duplication within complex glyphs.
This keeps large CJK fonts responsive even on limited hardware.
Why do font developers use CID for region-specific variants in East Asian typography?
CID allows multiple glyph shapes to coexist for regional standards like JIS, Big5, GB, or KS.
CMap files route text to the correct glyph version automatically.
This flexibility is essential for localization-sensitive scripts.
Why do CID-keyed fonts appear frequently in Ghostscript and TeX workflows?
These pipelines handle large multilingual documents that exceed the capacity of simple Type 1 fonts.
CID fonts integrate smoothly with PostScript-based interpreters.
They ensure consistent rendering across advanced typesetting systems.
Why does CID-keyed structure separate outlines from encoding?
It allows the same glyph set to be reused across different encodings and languages.
Encoding changes do not require regenerating the font itself.
This modularity simplifies maintenance in large font families.
Why do CID fonts store glyphs in FDArray groups?
FDArray allows different ranges of glyphs to use different font dictionaries or hinting strategies.
This is helpful for fonts mixing multiple writing styles or stroke patterns.
It optimizes memory usage and hinting accuracy for diverse glyph sets.
Why were CID-keyed fonts critical for early digital typography in East Asia?
Early computing systems struggled with the sheer number of glyphs required for CJK scripts.
CID provided the first scalable solution capable of representing complete national standards.
It enabled digital publishing on a global scale.
Why can converting CID-keyed fonts to non-CID formats be challenging?
CID fonts often contain thousands of glyphs and multiple CMap relationships.
Flattening these structures into a simple glyph list can result in mapping conflicts.
Advanced tools are required to preserve Unicode consistency.
Why is CID still used even though OpenType is the dominant font standard?
CID acts as the underlying organizational model for many OpenType CFF and CFF2 fonts.
Its scalability remains unmatched for large writing systems.
Because OpenType builds on CID logic rather than replacing it, the architecture continues to be crucial for multilingual typography.