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A* — Pathfinding

Interactive A* pathfinding widget: place walls, run the search step by step and watch the f = g + h heuristic at work, then compare it with Dijkstra.

JavaScript · Canvas · Algorithms

Repo Demo

A teaching demo I use in class to explain pathfinding. A* starts from Dijkstra and adds a priority towards the goal through an “as the crow flies” heuristic: it always explores the cell with the lowest cost f = g + h.

Things to try

  • Place obstacles (walls), move the start and the goal.
  • Use step by step or play to watch the order of exploration.
  • Compare the behaviour with and without the heuristic to grasp what A* brings.

The playable demo is embedded on this page (demoUrl field). Source code: see the repo link.