Create an A/B Split test using GravityForms

gform-split-test.php

<?php
/**
 * Create a split test using two different GravityForms
 *
 * Allows you to test the effectiveness of two different forms by displaying each
 * one 50% of the time. Tracking CTR using the built-in GravityForms functionality
 * should give you an idea of which form is most effective.
 *
 * @uses    GravityForms
 * @author  FAT Media, LLC
 */
function prefix_setup_gform_test( $id_1, $id_2 ) {

	// Do nothing if we have no forms.
	if ( ! $id_1 ||  ! $id_2 ) {
		return;
	}

	// Choose each form 50% of the time.
	$gform_id = mt_rand(0, 1) ? $id_1 : $id_2;

	// Display Subscribe Form
	$gravity_form = do_shortcode( '[gravityform id="' . $gform_id . '" description="false"]' );

	return $gravity_form;
}

// Display the forms.
echo prefix_setup_gform_test( 1, 2 );