Abstract. Given their critical role as gateways to Web content, the search results a Web search engine provides to its users have an out-sized impact on the way each user views the Web. Previous studies have shown that popular Web search engines like Google employ sophisticated personalization engines that can occasionally provide dramatically inconsistent views of the Web to different users. Unfortunately, even if users are aware of this potential, it is not straightforward for them to determine the extent to which a particular set of search results differs from those returned to other users, nor the factors that contribute to this personalization. We present the design and implementation of Bobble, a Web browser extension that contemporaneously executes a user's Google search query from a variety of different world-wide vantage points under a range of different conditions, alerting the user to the extent of inconsistency present in the set of search results returned to them by Google. Using more than 75,000 real search queries issued by over 170 users during a nine-month period, we explore the frequency and nature of inconsistencies that arise in Google search queries. In contrast to previously published results, we find that 98% of all Google search results display some inconsistency, with a user's geographic location being the dominant factor influencing the nature of the inconsistency.