What it does
FontGoggles is a free, open source macOS application for comparing font files. It previews compiled and source formats, OpenType features, variable axes and complex-script shaping.
Drop font files or folders into FontGoggles, then enter one test string to compare them together. Click a font to inspect its glyph positions. The Character and Glyph lists reveal how typed characters become drawn shapes, which helps explain ligatures and complex scripts where the two do not match one for one.
The Features panel cycles each OpenType feature between default, enabled and disabled; the Variations panel exposes the fonts’ axes. It can also preview UFO font sources and designspace files used to build variable families, reloading them when another editor saves changes. Compilation problems appear in the output panel.
A saved .gggls project keeps the comparison settings and relative paths to the fonts, so move those files together. FontGoggles is free and runs on macOS. Its HarfBuzz shaping and unhinted outlines may differ from the rendering in the application where a font will finally be used.
Strengths
- Compares fonts with shaping, feature and axis controls.
- Reloads source files and exposes compilation warnings.
Watch out for
- Available for macOS.
- Uses unhinted rasterisation and does not reproduce every target application.
Best for
- Type designers comparing source revisions.
- Developers investigating shaping and variation behavior.
Sources
- FontGoggles — Interactive Previewing and Comparing (Oct 27, 2026)