๐ณRecursion Tree Visualizer
Pick a recursive function, choose an input, and step through the actual call tree as it builds.
Runs entirely in your browser. No data is sent to a server.
Free Recursion Tree Visualizer
Recursion is easy to write and hard to see โ our free recursion tree visualizer makes it visible. Pick a classic recursive function like factorial or Fibonacci, choose an input, and watch the actual call tree build itself, call by call, with each node showing its arguments, its recursion depth, and eventually its return value.
Step through the animation at your own pace to see exactly when each call is made and when it returns โ and for Fibonacci, watch how quickly the number of calls explodes as n grows, a vivid illustration of why naive recursive Fibonacci is so inefficient without memoization.
Built for computer science students learning recursion, call stacks, and algorithmic complexity for the first time. No sign-up, no downloads โ just an interactive way to finally see how recursion works. See the About page or the FAQ for more.