CFF Converter

CFF (Compact Font Format) is a font outline format developed by Adobe Systems around 1996 as a more efficient successor to the Type 1 font representation. CFF uses Type 2 charstrings — an optimized encoding that supports multiple arguments per operator, default value elision, and shared subroutines — to describe the same cubic Bezier glyph outlines as Type 1 but with substantially less storage. A typical CFF font is 20-50% smaller than its Type 1 equivalent. The format can function as a standalone font file or, more commonly, as the outline data table inside an OpenType font container (the CFF table in OTF files with PostScript outlines). CFF supports multiple fonts within a single file through its FontSet structure, sharing global subroutines across the collection to further reduce size. One advantage is compression efficiency without lossy degradation — every control point and hint is preserved exactly, just encoded more compactly. The format also inherits the full hinting capability of Type 1, including stem hints, counter hints, and alignment zones that ensure crisp rendering on low-resolution screens and printers. CFF2, an evolution introduced with OpenType 1.8, adds support for font variations (variable fonts) by allowing interpolation across multiple design axes. Broad support in PDF viewers, web browsers via OpenType, and professional design software makes CFF one of the most widely deployed outline formats in digital typography.