288 published interactive labs
Simulation Hub — Interactive Simulations
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288 simulations found
Subnetting Calculator — Free Online IPv4 Subnet Tool
Free subnetting calculator — enter an IPv4 address and CIDR prefix to instantly see subnet mask, network/broadcast address, usable host range, and binary breakdown.
Advanced · 20+ minutesOpen simulation →technologyHow DNS Works — Interactive DNS Resolution Simulator
Watch a domain name resolve step by step through the DNS hierarchy: recursive resolver, root server, TLD server, and authoritative name server — plus the effect of caching.
Advanced · 20+ minutesOpen simulation →technologyOSI Model Explained — Interactive Packet Encapsulation
See data get encapsulated layer by layer through the OSI model — Application to Physical — with each header added and the PDU renamed from Data to Segment to Packet to Frame to Bits.
Advanced · 20+ minutesOpen simulation →technologyTCP 3-Way Handshake — Interactive Connection Simulator
Watch a TCP connection open with SYN, SYN-ACK, and ACK, exchange data, and close with FIN/ACK — including sequence numbers and each side's TCP state.
Advanced · 20+ minutesOpen simulation →technologyHTTP Request & Response — Interactive Simulator
Send GET, POST, PUT, and DELETE requests and read the raw HTTP response: status codes (200, 404, 301, 500), headers, and body. See how the web works.
Advanced · 20+ minutesOpen simulation →technologyPing & Traceroute Simulator — See Latency and Network Hops
Run ping to measure round-trip time and traceroute to reveal every router between you and a host — with TTL, per-hop latency, and min/avg/max RTT.
Advanced · 20+ minutesOpen simulation →technologyPacket Switching vs Circuit Switching Simulator — Why the Internet Shares Wires
See why the internet chops messages into packets instead of reserving a line. Compare circuit switching and packet switching, watch link utilization, and find the congestion cliff with statistical multiplexing.
Advanced · 20+ minutesOpen simulation →technologyStore-and-Forward & Pipelining Simulator — Why 3 Hops Aren't 3× Slower
See why a router must fully receive a packet before forwarding it, and how pipelining many packets across hops collapses total time from hops × packets to hops + packets − 1.
Advanced · 20+ minutesOpen simulation →technologyStatistical Multiplexing Simulator — Fit More Users on One Link
See why packet switching serves several times more users than circuit switching on the same link. Set capacity, per-user rate, and activity, and watch the multiplexing gain and overflow probability.
Advanced · 20+ minutesOpen simulation →technologyBuffer Overflow Simulator — Race Arrival Against Processing
Watch a finite buffer fill when data arrives faster than it can be processed, and drop packets when it's full — the exact failure that crashed the first ARPANET message in 1969.
Advanced · 20+ minutesOpen simulation →technologyNetwork Congestion Simulator — Why Delay Explodes Near Full Load
See how average queueing delay follows 1/(1−ρ) and shoots toward infinity as offered load approaches a link's capacity — the congestion cliff, plotted and animated.
Advanced · 20+ minutesOpen simulation →technologyDijkstra's Algorithm Visualizer: Shortest Paths on a Weighted Graph
Watch Dijkstra settle the closest node, relax its edges, and build a shortest-path tree on a weighted graph. See why a priority queue beats scanning, and predict which node gets settled next.
Advanced · 20+ minutesOpen simulation →technologyBig-O Complexity Visualizer: Compare O(1) to O(n!) on One Chart
Compare constant, logarithmic, linear, quadratic, exponential, and factorial growth on an interactive Big-O chart. Change input size and predict which complexity class grows faster.
Advanced · 20+ minutesOpen simulation →technologySudoku Solver Visualizer: Watch Backtracking Fill the Grid
Watch a backtracking algorithm solve Sudoku cell by cell, placing digits and undoing dead ends, or solve it yourself with live row/column/box conflict detection. See why pruning beats brute force.
Advanced · 20+ minutesOpen simulation →technologyTrie Visualizer: Prefix Tree, Autocomplete & O(L) Lookup
Build a trie and watch words share prefixes; search walks one node per letter, and autocomplete lights up every word beneath a prefix. See why lookup is O(L), independent of dictionary size.
Advanced · 20+ minutesOpen simulation →technologyBinary Heap Visualizer: Priority Queue, Sift-Up & Sift-Down
Build a binary min-heap and watch push bubble up and extract-min sift down, with the tree and its backing array shown together. See why a heap gives O(log n) priority-queue operations.
Advanced · 20+ minutesOpen simulation →technologyUnion-Find Visualizer: Disjoint Sets, Union by Rank & Path Compression
Click nodes to union sets and watch find() walk to the root. See how naive union builds an O(n) chain while union-by-rank and path compression flatten the forest toward near-constant inverse-Ackermann cost.
Advanced · 20+ minutesOpen simulation →technologyHash Table Visualizer: Chaining vs Linear Probing & Load Factor
Place keys into hash-table buckets and compare separate chaining with linear probing. Change the load factor, predict collisions, and observe how each strategy resolves them.
Advanced · 20+ minutesOpen simulation →technologyBinary Search Tree Visualizer: Insert, Search, Balanced vs Skewed
Watch values walk down a binary search tree on insert and search, and see why sorted inserts degenerate into an O(n) chain while shuffled inserts stay O(log n). Predict the search path yourself at each node.
Advanced · 20+ minutesOpen simulation →technologyEdit Distance Visualizer: Dynamic Programming Table You Fill Yourself
Watch the Levenshtein DP table fill cell by cell with live dependency arrows, trace the optimal alignment path, and test yourself by computing cells from their neighbors.
Advanced · 20+ minutesOpen simulation →technologyStack vs Queue Visualizer: LIFO and FIFO Side by Side
Push the same values into a stack and a queue at once and watch LIFO vs FIFO make their outputs diverge. Click the top or front to remove nodes; the lab enforces each structure's one-end access rule.
Advanced · 20+ minutesOpen simulation →technologyN-Queens Visualizer: Backtracking Search You Can Watch and Play
Watch backtracking place and undo queens row by row with attacked squares shaded live, then solve the board yourself. See why pruning turns an exponential search into a few thousand nodes.
Advanced · 20+ minutesOpen simulation →technologyRecursion Tree Visualizer: Fibonacci, Naive vs Memoized
Watch the Fibonacci call tree explode under naive recursion, then collapse with memoization. Click any node to light up every place that subproblem is recomputed, and see the call count fall from exponential to linear.
Advanced · 20+ minutesOpen simulation →technologySliding Window Visualizer: Max Subarray Sum, Brute Force vs O(n)
Compare brute-force O(n·k) re-summing with an O(n) sliding-window method. Move the window, inspect entering and leaving values, and measure the reduction in operations.
Foundation · Under 10 minutesOpen simulation →Learn science by changing the variables
SciFunLab turns equations into experiments. Compare a projectile motion simulation with the forces behind the Magnus effect, then investigate viscosity inside the fluid dynamics lab. Each page opens the working model directly, with no synthetic worksheet or course page between you and the experiment.
Advanced learners can trace light in the ray tracing lab, inspect atomic signals with NMR spectroscopy, model populations in the ecology simulation, or practise network design with the subnetting simulator.
Browse the engineering simulation collection, play browser physics games, or see how this catalogue compares as a PhET alternative for free interactive STEM exploration.