SEO Experiments | We Test Google's Algorithm To Uncover What Works

Cats Vs Dogs - Google Image Relevancy Experiment

An ongoing test to gauge Google's use of image text readability in the search results.

Google image reading experiment

An ongoing test to gauge Google's use of image text readability in the search results.

Duplicate content Image study

A long term SEO experiment studying the effect on rankings when embedding widely used stock images on your site compared with using your own unique images.

Hidden text experiment

This controlled SEO experiment examined the hypothesis that Google’s algorithms would prefer visible content over hidden content. The experiment clearly demonstrated Google’s preference for visible text.

Outgoing Links Experiment

A long-term SEO experiment examining the hypothesis that outgoing links may play a role in Google’s ranking algorithms. The results were conclusive. Results were kindly observed by Rand Fishkin from SparkToro prior to publication.

Long term shared hosting experiment

This technical experiment looked at the potential negative SEO effects of hosting a website on a shared IP address alongside 'bad neighbourhood' (low-quality, spammy and potentially malicious) type websites.

Rand Fishkin, Moz/Sparktoro

"They (RebootOnline) performed some wonderful, large-scale, long-term tests of CSS, of text area, of visible text, and of JavaScript hiding across many domains over a long period and basically proved to us that what Google says is in fact true, that they are treating this text behind here with less weight." - Rand Fishkin, Moz/Sparktoro

Neil Patel, Neilpatel.com

"I recently came across an interesting study from Reboot that measured outbound links as a ranking signal." - Neil Patel, Neilpatel.com (previously QuickSprout & KISSmetrics)

Barry Schwartz, Search Engine Roundtable

"WebmasterWorld has an SEO who tried an experiment, emailing 84 site owners across dozens of verticals, to see if they were interested in hiring his company to perform negative SEO. The results were pretty shocking." - Barry Schwartz, Search Engine Roundtable