size-adjust CSS at-rule descriptor

The size-adjust CSS descriptor for the @font-face at-rule defines a multiplier for glyph outlines and metrics associated with this font. This makes it easier to harmonize the designs of various fonts when rendered at the same font size.

The size-adjust descriptor behaves in a similar fashion to the font-size-adjust property. It calculates an adjustment per font by matching ex heights.

Syntax

css
size-adjust: 90%;

Values

<percentage>

A <percentage> value with an initial value of 100%.

All metrics associated with this font are scaled by the given percentage. This includes glyph advances, baseline tables, and overrides provided by @font-face descriptors.

Formal definition

Related at-rule@font-face
Initial value100%
Percentagesas specified
Computed valueas specified

Formal syntax

size-adjust = 
  <percentage [0,∞]>

Examples

undefined

Overriding metrics of a fallback font

The size-adjust property can help when overriding the metrics of a fallback font to better match those of a primary web font.

css
@font-face {
  font-family: "web-font";
  src: url("https://example.com/font.woff");
}

@font-face {
  font-family: "local-font";
  src: local("Local Font");
  size-adjust: 90%;
}

Specifications

See also