autokerning

autokerning computes suggested kerning values for glyph pairs from TrueType/OpenType fonts by rendering glyph bitmaps, applying a small Gaussian blur, and measuring pixel overlap across horizontal offsets. It can be used programmatically (as an imported ESM module) or via the included CLI.

Programmatic usage

Get kerning table (no file):

const kerning = await getKerningTable('./fonts/Roboto-Black.ttf', ['AV', 'To', 'Wa']);

Generate and save JSON:

const myPairs = ['AV', 'To', 'Wa']
const { outputPath } = await generateKerningTable('./fonts/Roboto-Black.ttf', {
  outputfile: 'Roboto-Black.json',
  pairs: myPairs,
  writeFile: true,
});

CLI Usage

# Print results for custom pairs
autokerning Roboto-Black.ttf AV WA To Ta ox

# Generate kerning JSON
autokerning Roboto-Black.ttf --output kerning.json