URL vs URL allows you to compare side-by-side your page with one or two competitors. You can select competitors from suggested pages, or type in whatever pages you want to compare. Click on Compare, and a diagram will show unique organic keywords of any of the pages, common keywords for all three pages, or of any two of the researched pages.
Clicking on any section of the diagram will generate examples of the keywords under the diagram. A full list of keywords can be received upon exporting the file.