Font weight

Font weight is how thick the strokes of the letters are, from thin and light to bold and black.

In CSS, weights are numbers from 100 to 900. 400 is regular and 700 is bold; many typefaces include only some of the weights in between.

Weight is one of the easiest ways to show what matters most. Pro tip: use a heavier weight for headings and a regular weight for body text, and limit yourself to two or three weights per screen.