font-size-adjust

Baseline 2024

Newly available

Since July 2024, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

Thefont-size-adjust attribute allows authors to specify an aspect value for an element that will preserve the x-height of the first choice font in a substitute font.

Note:As a presentation attribute,font-size-adjust also has a CSS property counterpart:font-size-adjust. When both are specified, the CSS property takes priority.

You can use this attribute with the following SVG elements:

Example

html,body,svg {  height: 100%;}

html

<svg  width="600"  height="80"  viewBox="0 0 500 80"  xmlns="http://www.w3.org/2000/svg">  <text y="20" font-family="Times, serif" font-size="10px">    This text uses the Times font (10px), which is hard to read in small sizes.  </text>  <text y="40" font-family="Verdana, sans-serif" font-size="10px">    This text uses the Verdana font (10px), which has relatively large lowercase    letters.  </text>  <text    y="60"    font-family="Times, serif"    font-size="10px"    font-size-adjust="0.58">    This is the 10px Times, but now adjusted to the same aspect ratio as the    Verdana.  </text></svg>

Usage notes

Default value	`none`
Value	`none` \|`<number>`
Animatable	Yes

none

Choose the size of the font based only on thefont-size property.

<number>

Choose the size of the font so that its lowercase letters (as determined by the x-height of the font) are the specified number times thefont-size.

The number specified should generally be theaspect ratio (ratio of x-height to font size) of the first choicefont-family. This means that the first-choice font, when available, will appear the same size in browsers, whether or not they supportfont-size-adjust.

0 yields text of zero height (hidden text).