ElementInternals: willValidate property

Baseline 2023

Newly available

Since March 2023, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

The willValidate read-only property of the ElementInternals interface returns true if the element is a submittable element that is a candidate for constraint validation.

Elements that are barred from being candidates for constraint validation include those that have the attributes: disabled, hidden or readonly, input elements of type=button or type=reset, or any element that is a <datalist> element or has a <datalist> element ancestor.


true if the element is a candidate for constraint validation, otherwise false.


NotSupportedError DOMException

Thrown if the element does not have its formAssociated property set to true.


The following example shows a custom checkbox component with formAssociated set to true, the value of willValidate is logged to the console.

class CustomCheckbox extends HTMLElement {
  static formAssociated = true;

  constructor() {
    this.internals_ = this.attachInternals();

  // …

window.customElements.define("custom-checkbox", CustomCheckbox);

let element = document.getElementById("custom-checkbox");
console.log(element.internals_.willValidate); // true


HTML Standard
# dom-elementinternals-willvalidate

Browser compatibility

BCD tables only load in the browser