AlgoScope is a visual lab for data structures and algorithms. Pick a lesson, press play, and watch the algorithm run one step at a time, then predict what happens next before it does.
Every lesson is a simulation you control: play, pause, step forward and back, scrub the timeline, change the speed, and enter your own input to see how the algorithm handles it. Each step has a one-line explanation of what just happened and why.
See it run
Watch binary search narrow the range, merge sort split and merge, and a binary search tree change shape as you insert and delete keys. Every value, pointer and comparison is on screen.
Interact
Type your own array, choose your own target, insert your own keys. The animation is generated from your input, not played from a recording.
Predict
At key moments the lesson stops and asks what happens next. Answer, then watch. This is what turns watching into understanding.
Understand
Short explanations sit on the exact step that raised the question. There are no chapters to read first.
What is inside
Every topic is interactive, from the first array to network flow.
Data structures: arrays, linked lists, stacks, queues, hash tables, binary search trees, AVL and red-black trees, heaps, tries, segment trees, Fenwick trees, disjoint sets.
Sorting and searching: every classic sort from bubble to radix, binary search and its variants, order statistics.
Graphs: BFS and DFS, Dijkstra, Bellman-Ford, Floyd-Warshall, Prim, Kruskal, topological sort, strongly connected components, bridges, max flow.
Techniques: dynamic programming, greedy, divide and conquer, backtracking, recursion, sliding window, two pointers, bit manipulation, string algorithms, number theory, computational geometry.
AlgoScope Pro
Every lesson is free. Pro is one optional purchase in the app, and it adds three things:
- Review queue: every predict-mode question you got wrong comes back until you get it right.
- Readiness: a score for every topic, from your answers, weakest first.
- Timed drills: the same lessons against a clock.
Pro belongs to your account, so it follows you to your other devices and the website. Restore purchases is on the AlgoScope Pro screen in Settings.
Made for studying
- Every lesson works offline, because the lessons are on your device.
- Every lesson works without an account, and there are no ads.
- An optional free account, with Apple, Google or email, keeps your progress in step across your iPhone, iPad and the website.
- iPhone and iPad layouts.
- Dark theme, reduced motion, screen-reader labels on every element, and colours chosen to stay readable with colour-blindness.
- Deterministic: the same input always produces the same steps, so a lesson can be repeated exactly.
Who it is for
Computer science students meeting data structures for the first time. Anyone preparing for a placement, an exam or a coding interview who wants to understand the algorithm rather than memorise the answer. Teachers who want a visualization that responds to the class's own examples.
Privacy
Without an account, nothing about you is sent to us. If the app crashes, a crash report goes to Google so it can be fixed: what failed, the device model and the app version. Usage sharing is off unless you turn it on in Settings. With an account, your progress, predict-mode answers and Pro purchase are saved to it so they follow you, and you can delete the account in Settings at any time. No ads, no advertising ID, no tracking. The full policy is linked on this page.
If a lesson could be clearer, tell us through the support link.
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