:valid

:valid is a CSS pseudo-class used to select and style form <input> elements whose values validate according to their type specified in the type attribute.

For example, email inputs (<input type="email">) whose values match a valid email address pattern.

Trivia & Notes

When a number input type (<input type="number">) is in the range of permitted values specified using the min and max attributes, then the :valid pseudo-class matches, and also the :in-range pseudo-class matches. Any styles applied using :in-range will override the styles applied using :valid only if the :in-range styles come after the :valid styles in the style sheet.

Just like other pseudo-class selectors, the :valid selector can be chained with other selectors such as :hover and :focus, among others. For example, the following rule will provide focus styles for the element that is in an valid state, adding a soft green glow around it:

 input:valid:focus { outline: 0; border: none; box-shadow: 0 0 3px 6px rgba(0, 200, 0, 0.3); } 

You can see a live demo of this in the live demo section below.

 input[type="number"]:valid { background-color: lightgreen; } input:valid { box-shadow: 0 0 3px 5px rgba(0, 200, 0, .2); }