Google FINALLY Admits That GWO Could F*** Up Your Rankings

Google’s official line on their Google Website Optimizer (GWO) A/B testing tool was that using it would not make your site trip a cloaking filter (since essentially A/B or MVT testing shows different versions of the same page to different people). They claimed it was SEO-safe in other words.


At Pubcon Las Vegas in 2010 I presented a case study showing how using GWO on my dad’s site,, resulted in most of his rankings dropping like a rock, starting when he was crawled next after we implemented the test.

With Google’s announcement last week that Google Website Optimizer would be folded into Google Analytics and that GWO would be renamed “Content Experiments,” the following suggestion was posted on the help section :

“To ensure that serving your variation pages does not have a negative impact on your site’s SEO rankings, you can use the rel=”canonical” link attribute on your variation pages. rel=”canonical” is a signal to search engines that the content of your variation pages is essentially the same as that of your original page, and that you would prefer that search engines index your original page rather than the variations you’re using in your experiment.”

My solution back in the day called for putting your variation pages in search engine-unfriendly wrappers such as Flash, frames or javascript, and noindex-ing them for good measure. Since rel=canonical of course, the process is officially simpler. At least, that’s what Google says ;).

This is a guest post by @GabGoldenberg. If you like this, you might like my advanced SEO book, which teaches critical/creative thinking for SEO, and shares 30 new tactics. You can get a free chapter now.

Want to read more? Check out my guide on using WP with Google Website Optimizer despite GWO being designed for sites not based on a CMS.

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