Ascender
An ascender is the part of a lowercase letter that extends above the x-height, as in 'b', 'd', 'f', 'h', 'k', 'l', and 't'. The ascender height is typically equal to or slightly taller than the cap height.
In Practice
The ascender is the portion of a lowercase letter that extends above the x-height, visible in letters like b, d, f, h, k, l, and t. Ascender height varies between typefaces; when two fonts are set at the same nominal size, the one with taller ascenders will look slightly larger. This affects visual alignment when pairing typefaces. The ascender height is one of the key metrics listed in the font inspector when you drop a font file to analyze.
Common Mistakes
The common mistake with most typographic terms is applying them without considering how they interact with other settings. Type is a system: changing kerning affects tracking, changing size affects leading, changing measure affects line-height. Test changes in context rather than in isolation.
Ascenders and apparent size
Ascenders are the parts of letters that rise above the x-height, visible in b, d, f, h, k, l, and t. Their height varies from font to font, and it changes how large a face looks at the same nominal size: a font with tall ascenders and a low x-height reads as airier, while one with short ascenders and a tall x-height looks full and compact.
There is no CSS property for ascender height, so when two fonts share a line and one has visibly taller ascenders, the difference shows up as uneven color in the text block. This matters most in headlines set in a display face above body copy in a text face. The fonts page lists each family's category and mood; comparing two candidates there makes it easier to spot which one will draw the taller ascenders.