jQuery AJAX form submits twice

It's most likely that you're using a button or submit to trigger the ajax event. Try this:

$('#exportForm').submit(function(e){
        e.preventDefault();
        $.ajax({
            type: "POST",
            url: $(this).attr( 'action' ),
            data: $(this).serialize(),
            success: function( response ) {
                console.log( response );
            }
        });

        return false;
    });

In case you are using some kind of validation (e.g jQuery Validation), the form is submitted twice because aside from $('#exportForm').submit you write yourself, the validation plugin will also submit the form after it successfully validates all field.

NB : If you are using jQuery Validation, avoid using .submit(). Instead, use submitHandler.

As well as calling preventDefault, also call stopImmediatePropagation on the event.

$('#exportForm').submit(function(e){
    e.preventDefault();
    e.stopImmediatePropagation();
    $.ajax({
        type: "POST",
        url: $(this).attr( 'action' ),
        data: $(this).serialize(),
        success: function( response ) {
            console.log( response );
        }
    });

    return false;
});