secretsofmaps.com hosts a set of interactive visualizations of various routing algorithms: BFS1, DFS2, Bidirectional BFS, Greedy, A*, Bidirectional A*, and A* plus Lookup Table. The whole site is a kind of interactive tutorial that guides you sequentally through the routing algorithms.
The site says “How does Google Maps work? – Explore the algorithm”. But as far as I could see the site is not affiliated with Google. It is built by Adam Kulikowski based on earlier work by Jan Pánek.
Recommendation for the more trivial algorithms: Use the slider to speed up the animations.