====== 10.2.2. Only use relative sizes (em, %, small, etc.) for typefaces ======

To define the size of character fonts, only use relative units for the ''CSS font-size'' property, such as ''em'', ''%'', ''px'', ''rem'', and the keywords ''x-small'', ''small'', etc.

Do not use absolute unit sizes, such as ''pt'', ''cm'', etc.

<note attention>**Warning**

Due to its poor support in Internet Explorer, using pixels (px) as a unit of font size is not authorized in some guidelines such as the French guidelines AccessiWeb or RGAA. To ensure conformity with these guidelines, you must use a different unit of size for the ''font-size'' property.
</note>

===== Related recommendations =====

<note bulle>
  * Previous recommendation: [[notices:html-css:utiliser-css-pour-mettre-en-forme-les-textes]]
  * Next recommendation: [[notices:html-css:garantir-la-lisibilite-des-contenus-jusqu-a-200-de-grossissement]]
</note>