Algorithm Visualizations
Watch algorithms come to life. Press play, slow it down, or step through one operation at a time - then learn the code with free interactive lessons.
What is an algorithm visualizer?
An algorithm visualizer turns abstract steps into a moving picture. Instead of reading pseudocode and imagining what happens, you watch the data change: bars swap into place as a sorting algorithm runs, nodes light up as a graph is traversed, and pointers rewire as a tree rebalances. Seeing each operation makes the logic - and the reason behind its time complexity - far easier to remember.
Every visualization on Coddy is free, needs no sign-up, and runs right in your browser. Press play to watch an algorithm run start to finish, slow it down, or step through one operation at a time. Each page also shows the complexity, a step-by-step breakdown, and the actual code, so you can move from watching to writing it yourself.
How to use these visualizers
- Pick a category, then choose an algorithm or data structure.
- Press play to watch it run, or step through one operation at a time.
- Change the input and speed to test edge cases and build intuition.
- Read the complexity table and code, then try it yourself in a free lesson.