Step Through

Can't follow the textbook?Step through it yourself.

Algorithms and data structures as visualizations you operate by hand — step forward, step back, and read one plain sentence on what is happening and why.

Browse topicsStart with insertion sort →
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Insertion sort | step 7 of 26Compare 5 with key 4: 5 is larger, so shift 5 one place right and move the hole left.A real frame from the middle of a run. Open the topic to enter your own data and step forward, back, or to any step.

Topic index

Ordered the way a data structures course teaches them.

Sorting

Trees

  • Binary Search TreeComing soon
  • AVL Tree InsertionComing soon
  • Heap and Heap SortComing soon
  • Red-Black TreeComing soon

Hashing and systems

  • Hash Table CollisionsComing soon
  • Page ReplacementComing soon
  • TLB Hits and EATComing soon
  • Cache MappingComing soon

Graphs and DP

  • DijkstraComing soon
  • Dynamic Programming TablesComing soon

How this differs from static diagrams and play-only animations

Use your own data

No fixed animation. Type an array or load the best or worst case, and it reruns at once.

Every step says why

A plain sentence beside the stage: what was compared, why it swaps, with the current pseudocode line marked.

Go back any time

Previous, next, drag the timeline, or use ← → and Space on the keyboard.