kerning

Kerning is the typographic adjustment of the horizontal space between specific character pairs to achieve visually even spacing along a line of text. The aim is to correct gaps that arise from the shapes of letters, ensuring a uniform density and rhythm across words and lines.

Kerning is distinct from tracking (or letter-spacing). Tracking adjusts the spacing uniformly across a range of characters, whereas kerning targets individual pairs or small groups to compensate for particular shapes and optical balance. In professional typesetting and digital typography, kerning values are stored in font data (often in a kern table within OpenType fonts) and can be applied automatically by software or adjusted manually.

There are two main approaches to kerning. Metric kerning uses predefined spacing adjustments contained in the font. Optical kerning, by contrast, uses algorithms to adjust spacing based on the actual shapes of glyphs, which can produce more balanced results in certain fonts or at certain sizes. Many fonts include kerning pairs, but automatic kerning can be enabled or disabled in design software.

Historically, kerning arose from metal type, where spaces had to be manually altered for visual balance. In digital design, kerning remains essential for headlines, logos, and any text where precise visual harmony is important. Kerning sensitivity often varies by size, font, and rendering method; excessive or insufficient kerning can reduce readability and aesthetic quality.