Algorithm, data structure and ML visualizers
Choose a topic, explore its explanation and watch the steps unfold. These interactive learning tools are free to use.
Algorithms
Longest Subarray Sum K Visualizer
Visualize the longest subarray with sum K using a sliding window. Follow the left and right pointers and see when the window expands or shrinks.
Spiral Matrix Traversal Visualizer
Watch spiral matrix traversal step by step. Follow the shrinking boundaries and see how each row and column contributes to the output.
Rotate Matrix 90 Degrees Visualizer
Visualize rotating a matrix 90 degrees in place. Follow the transpose and row reversal steps with an interactive matrix animation.
Sorting Algorithm Visualizer
Visualize bubble sort, selection sort, quicksort and merge sort. Step through comparisons, swaps and array updates to understand each algorithm.
Binary Search Visualizer: Step-by-Step Animation
Explore binary search with an interactive sorted array. Follow low, mid and high pointers, try a target and understand logarithmic search.
Floyd Cycle Detection Visualizer
Watch Floyd's tortoise and hare algorithm detect a linked list cycle. Step through slow and fast pointers, find the cycle entry or the middle node.
Dynamic Programming Visualizer
Explore dynamic programming with interactive table updates and answer reconstruction. Follow each state transition and see how subproblems build a solution.
Topological Sort Visualizer: Kahn's Algorithm
Step through Kahn's topological sort, track in-degrees and detect cycles. Explore union-find with interactive graph examples on CodeQuest101.
N-Queens Backtracking Visualizer
Visualize the N-Queens problem with step-by-step backtracking. Watch queen placements, conflicts and undo steps while exploring the search tree.
Data Structures
Binary Tree Traversal Visualizer
Explore binary tree traversals with interactive animations. Follow depth-first and breadth-first visits and compare traversal orders.
Linked List Visualizer
Explore linked list operations with an interactive pointer visualization. See how nodes connect and how links change during each operation.
Stack and Queue Visualizer
Visualize stack and queue operations. Compare LIFO and FIFO behavior, track inserted and removed elements and explore each data structure interactively.
Binary Search Tree Visualizer
Explore tree insertion, deletion, search and traversal. Watch how binary search tree operations change nodes and follow the explanation for each step.
Graph Algorithm Visualizer: BFS and DFS
Build a graph and explore breadth-first and depth-first traversal. Follow visited nodes and edges to understand how BFS and DFS explore a graph.
Heap and Priority Queue Visualizer
Explore heap operations with an interactive priority queue visualization. See how parent-child ordering changes during insertion and removal.
Trie Visualizer: Prefix Tree and Autocomplete
Insert words, search prefixes and explore autocomplete with an interactive trie visualizer. Follow each character through the prefix tree.
Interview Patterns
Arrays and Hashing Interview Pattern Visualizer
Learn arrays and hashing through animated coding interview problems, including Two Sum and anagrams. Compare approaches and explore Python solutions.
Two Pointers Visualizer: Step-by-Step Examples
Learn the two pointers technique with interactive palindrome, 3Sum and trapping rain water examples. Follow pointer decisions and compare with brute force.
Sliding Window Visualizer: Step-by-Step Examples
Explore fixed and variable sliding windows with interactive substring and subarray examples. Follow pointer moves, compare brute force and study Python solutions.
Stack Interview Pattern Visualizer
Learn stack interview patterns with animated bracket matching, reverse Polish notation and monotonic stack examples. Explore explanations and Python solutions.
Binary Search Interview Pattern Visualizer
Explore binary search interview problems with animated rotated arrays, Koko eating bananas and median examples. Follow the search boundaries step by step.
Linked List Interview Pattern Visualizer
Learn linked list interview patterns with pointer animations for reversal, cycle detection and LRU cache problems. Explore explanations and Python solutions.
Tree Interview Pattern Visualizer
Explore tree interview patterns with interactive DFS, BFS, binary search tree and path sum problems. Follow each step and study Python solutions.
Machine Learning & AI
Gradient Descent Visualizer: Learning Rate and Optimizers
Explore gradient descent with interactive learning rates, loss contours and optimizer comparisons. See how SGD, momentum and Adam move toward a minimum.
Linear Regression Visualizer
Fit a line interactively and explore linear regression. See how predictions, residuals and loss change as the model learns from data.
K-Means Clustering Visualizer
Explore K-means clustering with interactive points and centroids. Follow cluster assignments and centroid updates to see how unlabeled data forms groups.
Decision Tree Visualizer
Explore decision tree splits, Gini impurity and overfitting interactively. See how feature thresholds divide data and build a classifier.
Naive Bayes Visualizer
Explore a Naive Bayes spam classifier interactively. See how word likelihoods and prior probabilities combine to classify a message.
Random Forest Visualizer
Explore random forests through interactive decision trees, bootstrap samples and out-of-bag evaluation. See how individual trees vote on a prediction.
Gradient Boosting Visualizer
Visualize gradient boosting step by step. See how each new decision tree fits residual errors and improves the combined prediction.
Neural Network Training Visualizer
Train a neural network interactively. Explore forward propagation, backpropagation and weight updates to see how a model learns from data.
Self-Attention Visualizer: Query, Key and Value
Explore transformer self-attention with interactive query, key and value matrices. Follow attention scores and see how tokens combine information.
LLM Sampling Visualizer: Temperature, Top-K and Top-P
Explore LLM token sampling with interactive temperature, top-k and top-p controls. Follow logits, softmax probabilities, filtering and the final token draw.