opentype.js is a JavaScript library that reads and writes OpenType fonts in the browser and Node.js.
The library solves the problem of programmatically accessing and manipulating font data by parsing OpenType font files into usable objects. It converts text into bézier paths derived from font letterforms, allowing developers to work with glyph data, kerning information, and ligatures. The tool supports multiple font formats including WOFF, OTF, TTF with both TrueType and PostScript outlines, and handles advanced typography features like composite glyphs, TrueType hinting, Arabic text rendering, and color glyphs in SVG or COLR/CPAL formats.
Developers should choose this library when they need to extract or manipulate font data in web or Node.js environments. It suits projects requiring glyph path generation, font analysis, or dynamic text rendering with precise control over letterforms. The README does not name alternatives for comparison.
The project maintains a formal release process using a manual workflow that includes preflight checks and dry-run validation before publishing. Development follows a structured contribution model with build, development server, and test commands available to contributors.
