This article applies to Nelio A/B testing versions prior to 5.0.

If you are looking for documentation for our newest version, please bookmark

Nelio A/B Testing differs from other A/B Testing services because alternative content is served directly from your WordPress server, instead of modifying the DOM of your pages. In order to load the appropriate content, our tracking JavaScript is responsible of including one or more GET parameters in the URL. These parameters will tell our plugin (which is installed in your server) which alternative content has to be loaded.

I see alternative headlines, but still there are no page views

When running Headline Experiments, Nelio A/B Testing will hook into several WordPress hooks (such as, for instance, the_title or get_he_excerpt) and will replace the original headlines with the alternative values. The list of headlines that were replaced within a page are included in the wp_footer. Our tracking script reads the list of replaced headlines and sends the information to our backend servers.

If you see alternative headlines when accessing, for instance, your Latest Posts, it means that our plugin worked properly (the first hooks worked). The fact that there are no page views in your experiment is probably because the list of replaced headlines was not included in the page; that is, wp_footer is not being used by your theme (even though it should).

In order to fix this, simply edit the file footer.php in your theme and add, right before the body tag is closed, the following code:

<?php wp_footer(); ?>

For instance, WordPress official theme Twenty Fifteen has the following footer.php file:



 * The template for displaying the footer


 * Contains the closing of the "site-content" div and all content after.


 * @package WordPress

 * @subpackage Twenty_Fifteen

 * @since Twenty Fifteen 1.0



  </div><!-- .site-content -->

  <footer id="colophon" class="site-footer" role="contentinfo">

    <div class="site-info">



         * Fires before the Twenty Fifteen footer text for footer customization.


         * @since Twenty Fifteen 1.0


        do_action( 'twentyfifteen_credits' );


      <a href="<?php

        echo esc_url( __( '', 'twentyfifteen' ) ); ?>"><?php

        printf( __( 'Proudly powered by %s', 'twentyfifteen' ), 'WordPress' ); ?></a>

    </div><!-- .site-info -->

  </footer><!-- .site-footer -->

</div><!-- .site -->

<?php wp_footer(); ?>



Alternative Headlines are not visible alwaysin some pages or widgets they work, in others they don't

If headlines are replaced sometimes, but not always, there are two possible explanations:

  1. A widget/plugin does not use the appropriate WordPress hooks. When that occurs, Nelio A/B Testing has no way to capture that headline and replace it with the alternative content.

  2. You're loading content using an AJAX request. Some pages load content dynamically using AJAX request. Usually, these AJAX request do not contain any information about the alternatives a visitor is supposed to see, which means that our plugin will not be able to replace headlines properly.

If you're facing the first scenario, just contact our support team and let us know which plugin/widget are you using so that we can look into your problem.

If, on the other hand, you're facing the second one, you'll have to tweak your AJAX calls. If you have trouble doing so, just contact our support team and we'll help you.