fontmake

fontmake is a command-line tool for compiling fonts from source files to OpenType binary format, developed by the Google Fonts team. With over 2,800 stars as of 2026, fontmake is the standard build tool for modern typeface design, used in the Google Fonts open-source font pipeline and by professional type foundries worldwide. fontmake takes UFO (Unified Font Object) and Glyphs source formats as input and produces OTF (OpenType with CFF outlines), TTF (TrueType with quadratic outlines), WOFF, and WOFF2 output files. Key features include: UFO source format support (version 2 and 3, including designspace files for variable fonts), Glyphs source format support (the popular macOS font editor file format via glyphsLib), automatic OpenType feature compilation (converting Adobe Feature File .fea syntax into GPOS/GSUB tables via feaLib), instance generation (creating static font instances from variable font definitions with configurable axis values), automatic removal of overlapping paths (via booleanOperations), autohinting (applying TrueType hints via ttfautohint for TTF output and Adobe autohint for CFF output), variable font compilation (producing OpenType variable fonts with designspace axes and variation tables), web font optimization (generating WOFF2 compressed output), family naming automation (applying proper OpenType name table entries), batch processing (compiling multiple masters and instances in a single run), and integration with the Google Fonts engineering pipeline (used to build all 1,500+ open-source font families in the Google Fonts library). fontmake is written in Python and built on top of FontTools, ufo2ft, glyphsLib, cu2qu, and booleanOperations.