jQuery add required to input fields

You can do it by using attr, the mistake that you made is that you put the true inside quotes. instead of that try this:

$("input").attr("required", true);

I have found that the following implementations are effective:

$('#freeform_first_name').removeAttr('required');

$('#freeform_first_name').attr('required', 'required');

These commands (attr, removeAttr, prop) behave differently depending on the version of JQuery you are using. Please reference the documentation here: https://api.jquery.com/attr/

Using .attr method

.attr(attribute,value); // syntax

.attr("required", true);
// output: required="required"

.attr("required", false);
// output:

Using .prop

.prop(property,value) // syntax

.prop("required", true);
// output: required=""

.prop("required", false);
// output: 

Read more from here

https://stackoverflow.com/a/5876747/5413283

Should not enclose true with double quote " " it should be like

$(document).ready(function() {            
   $('input').attr('required', true);   
});

Also you can use prop

jQuery(document).ready(function() {            
   $('input').prop('required', true);   
}); 

Instead of true you can try required. Such as

$('input').prop('required', 'required');

I found that jquery 1.11.1 does not do this reliably.

I used $('#estimate').attr('required', true) and $('#estimate').removeAttr('required').

Removing required was not reliable. It would sometimes leave the required attribute without value. Since required is a boolean attibute, its mere presence, without value, is seen by the browser as true.

This bug was intermittent, and I got tired of messing with it. Switched to document.getElementById("estimate").required = true and document.getElementById("estimate").required = false.