Heuristics are at the heart of every planner. From the simple to the complex, they drive both satisficing and optimal planning approaches. Despite their pervasiveness, there has been relatively little effort towards systematically visualizing them. We introduce a plugin for the online editor at Planning.Domains that is capable of visualizing the heuristic computation of a manually explored state space. Our initial implementation demonstrates the hadd heuristic, but the framework serves as an extensible base for other heuristics in the field of automated planning.