SERP Similarity by TopicalMap.com is a free Chrome extension designed to compare the active Search Engine Results Pages (SERPs) with those of another search query. By utilizing this tool, users can easily analyze and contrast the Google SERPs page they are currently viewing with the results of a different query.

To use the extension, simply navigate to Google SERPs, click on the Topical Map icon button, input the desired search query for comparison, and allow the background tab to load completely. The extension's popup box will then display the SERPs and highlight any matches found between the two queries.