HTMLInputElement: readOnly property

The readOnly property of the HTMLInputElement interface indicates that the user cannot modify the value of the <input>. It reflects the <input> element's readonly boolean attribute; returning true if the attribute is present and false when omitted.

Unlike a form control with a true disabled property, a true readOnly property value does not prevent the user from clicking or selecting in the control.

While the HTML readonly attribute is ignored if the type is hidden, range, color, checkbox, radio, file, submit, reset, button, and image, the readOnly property is true for these input types if the attribute is present, false otherwise.

const inputElement = document.getElementById("total");
console.log(inputElement.readOnly);
inputElement.readOnly = true;