George Stephanis calls himself a code monkey. He is a developer at Speck Products and a Core Contributor at WordPress. We asked him a couple questions about the technical side of A/B testing.

Optimizely: How does A/B testing affect my page load time?

George: Split or A/B testing as a concept doesn’t need to affect page load times at all.  You could, for instance, split the versions on the server-side in your Content Management System (Magento, WordPress, Drupal, whatever you’re using), so that two versions of a page are being delivered to users.  Javascript tools such as Optimizely are completely client-side, and these may add some additional load time onto your pages.  And even then, the size of the Optimizely script is largely dependent upon whether it has to bundle jQuery in with itself (which it does by default) or if you are already using jQuery in your website — in which case it could reduce the size of the base Optimizely script from 35kb to 17kb excluding jQuery. This is of course neglecting the fact that the script will be cached for subsequent page loads, not needing to redownload itself — but even so, the load time of the first page on your site is typically understood as the most important.

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