2.4.13: Focus Appearance [AAA]


When the keyboard focus indicator is visible, an area of the focus indicator meets all the following:

  • is at least as large as the area of a 2 CSS pixel thick perimeter of the unfocused component or sub-component, and
  • has a contrast ratio of at least 3:1 between the same pixels in the focused and unfocused states.


  • The focus indicator is determined by the user agent and cannot be adjusted by the author, or
  • The focus indicator and the indicator's background color are not modified by the author.
Note 1

What is perceived as the user interface component or sub-component (to determine enclosure or size) depends on its visual presentation. The visual presentation includes the component's visible content, border, and component-specific background. It does not include shadow and glow effects outside the component's content, background, or border.

Note 2

Examples of sub-components that may receive a focus indicator are menu items in an opened drop-down menu, or focusable cells in a grid.

Note 3

Contrast calculations can be based on colors defined within the technology (such as HTML, CSS and SVG). Pixels modified by user agent resolution enhancements and anti-aliasing can be ignored.