The font-size-adjust property of CSS tells the browser to adjust the font size of the text to the same size regardless of font family. When the first chosen font is not available, the font-size-adjust property allows you more control over the font size. If a font isn’t available, the window defaults to the second font defined. This could lead to a significant shift in font size. Using the font-size-adjust property to stop this. The size difference between the lowercase letter “x” and the uppercase letter “X” is the “aspect value” of all fonts. When the browser knows the “aspect value” of the first font, it will determine what font-size to use when viewing text in the second font.
Below are the examples that illustrates the use of font-size-adjust property.
Only Firefox currently supports the CSS font-size-adjust property by default.