jQuery validate plugin: validate on blur() by default

jQuery Validation is "Lazy" validation by default. This means that, before the submit is clicked the first time, much of the validation is ignored when moving from field to field.

You're requesting "Eager" validation, so simply over-ride the onfocusout default with a custom function...

$('#yourForm').validate({
    // rules, options, etc.,
    onfocusout: function(element) {
        // "eager" validation
        this.element(element);  
    }
});

Documentation: http://jqueryvalidation.org/validate/#onfocusout

Additional Reference: https://stackoverflow.com/a/28114269/594235

Default onfocusout function:

onfocusout: function(element) {
    // "lazy" validation by default
    if (!this.checkable(element) && (element.name in this.submitted || !this.optional(element))) {
        this.element(element);
    }
},