What CSS property controls the spacing between letters?

The CSS property that controls spacing between letters is letter-spacing. It adjusts the horizontal space inserted between successive characters, making text appear more open or more tightly packed.

Positive values increase tracking, while negative values reduce it. A declaration such as `letter-spacing: 0.08em` is often used for headings, navigation labels, or all-caps text. Relative units such as `em` scale with the element’s font size, while fixed units such as pixels provide a specific adjustment.

Letter-spacing is different from word-spacing, which changes the gaps between words, and line-height, which changes the distance between lines. It is also different from kerning: letter-spacing applies a broadly uniform adjustment, whereas kerning fine-tunes particular character pairs such as “A” and “V”. The property dates back to CSS1, the first major CSS recommendation published in 1996.