Only a small subset of CSS properties can be used in a rule with ::spelling-error in its selector:

• color
• background-color
• cursor
• caret-color
• outline and its longhands
• text-decoration and its associated properties
• text-emphasis-color
• text-shadow

In this example, eventual supporting browsers should highlight any flagged spelling errors with the styles shown.

HTML

<p contenteditable spellcheck="true">
  My friends are coegdfgfddffbgning to the party tonight.
</p>

CSS

::spelling-error {
  text-decoration: wavy red;
}

Result

• ::grammar-error