Data Structure Visualizer
See data structures build and rearrange, step by step
A data structure visualizer animates how a structure stores and reorganises data — watch a binary search tree rebalance after an insert, a hash table resolve a collision, or a stack push and pop. Seeing the operations makes their time complexity intuitive.
Pick a structure below to insert, delete and search interactively, and read how each operation performs in Big-O terms.
Browse Visualizers
Binary Search Tree Visualizer
Keeps keys ordered for O(log n) search, insert and range queries. Watch it rebalance as you add nodes.
Binary Heap Visualizer
A partially-ordered tree that surfaces the min or max in O(log n) — the engine behind priority queues and heap sort.
Stack Visualizer
Last-in, first-out (LIFO). Push and pop in O(1); the structure behind undo, recursion and DFS.
Queue Visualizer
First-in, first-out (FIFO). Enqueue and dequeue in O(1); the structure behind scheduling and BFS.
Linked List Visualizer
Nodes chained by pointers — cheap insertion and deletion anywhere, at the cost of no random access.
Hash Table Visualizer
Maps keys to buckets via a hash function for average O(1) lookup. Watch how collisions are resolved.
Why visualize data structures?
Choosing the right data structure is what separates a slow program from a fast one — and the trade-offs (O(1) hash lookup vs O(log n) ordered tree, array vs linked list) are far easier to grasp when you watch the operations happen. These visualizers are built for students, coding-interview prep, and anyone teaching or learning how the core structures work.
Frequently asked questions
What is a data structure visualizer?
An interactive tool that animates the operations of a data structure — inserts, deletes, searches, rebalances — so you can see how it stores data and why each operation has a given time complexity.
When should I use a hash table versus a binary search tree?
Use a hash table for fast key lookups when order does not matter — average O(1). Use a binary search tree when you need keys kept in sorted order, range queries, or ordered traversal — O(log n) on a balanced tree.
Are these visualizers free?
Yes. Every visualizer runs entirely in your browser, free, with no signup and no data leaving your device.