The element's custom validity message has been set to a non-empty string by calling the element's setCustomValidity() method.
The value does not match the specified pattern.
The value is greater than the maximum specified by the max attribute.
The value is less than the minimum specified by the min attribute.
The value does not fit the rules determined by the step attribute (that is, it's not evenly divisible by the step value).
The value exceeds the specified maxlength for HTMLInputElement or HTMLTextAreaElement objects.
The value is not in the required syntax (when type is email or url).
The element meets all constraint validations, and is therefore considered to be valid.
The element has a required attribute, but no value.