HTMLButtonElement: validity property

The validity read-only property of the HTMLButtonElement interface returns a ValidityState object that represents the validity states this element is in.

Value

A ValidityState object.

Examples

The following example demonstrates that a <button> is in an invalid state when a customError is set; in this state, the validityState’s validity property is false, while checkValidity() returns true if the button’s type is not "submit", because such buttons are not candidates for constraint validation.

const button = document.getElementById("myButton");
button.setCustomValidity("This button is invalid.");
const validityState = button.validity;
console.log(validityState.valid); // false
console.log(validityState.customError); // true
console.log(button.checkValidity()); // false if the button is of the "submit" type, true otherwise

Specifications

Browser compatibility

See also

• checkValidity()
• <button>
• <form>
• Learn: Client-side form validation
• Guide: Constraint validation