:focus

The :focus CSS pseudo-class represents an element (such as a form input) that has received focus. It is generally triggered when the user clicks or taps on an element or selects it with the keyboard's "tab" key.

/* Selects any <input> when focused */
input:focus {
  color: red;
}

Syntax

:focus

Example

HTML

<input class="red-input" value="I'll be red when focused."><br>
<input class="blue-input" value="I'll be blue when focused.">

CSS

.red-input:focus {
  background: yellow;
  color: red;
}

.blue-input:focus {
  background: yellow;
  color: blue;
}

Result

Accessibility Concerns

Make sure the visual focus indicator can be seen by people with low vision.  This will also benefit anyone use a screen in a brightly lit space (like outside in the sun).   WCAG 2.1 SC 1.4.11 Non-Text Contrast requires that the visual focus indicator be at least 3 to 1. 

• Accessible Visual Focus Indicators: Give Your Site Some Focus! Tips for Designing Useful and Usable Focus Indicators

:focus { outline: none; }

Never just remove the focus outline (visible focus indicator) without replacing it with a focus outline that will pass WCAG 2.1 SC 1.4.11 Non-Text Contrast

• Quick Tip:  Never remove CSS outlines

Specifications

Browser compatibility

See also

• :focus-visible 
• :focus-within