104 live simulators across 9 subjects. Search or filter by subject, class, topic or difficulty. Class matches follow CBSE/NCERT topics as a guide; check your current syllabus.
Open a specific lesson inside a lab.
Six sorts get the same input and each plays one step of its animation per tick. A step is roughly one comparison or one move, so the finishing order shows how much work each one does on this input.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Sorting raceWalk through the array and swap any neighbors that are out of order. After each pass, the largest remaining value has bubbled to the end.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Bubble sortFind the smallest value in the unsorted part and swap it to the front. Repeat until nothing is left.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Selection sortKeep the left part sorted. Take the next value (the key) and slide it left past every bigger value.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Insertion sortInsertion sort, but first on values that are gap apart. Big gaps move far-away values quickly; the last pass with gap 1 is a normal insertion sort on an almost sorted array.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Shell sortSplit the array in half until each piece has one value, then merge the pieces back together in order.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Merge sortPick a pivot, move smaller values to its left and bigger ones to its right, then sort each side the same way.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Quick sortTurn the array into a max-heap so the biggest value sits at index 0. Swap it to the end, shrink the heap by one, and repair it. Repeat.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Heap sortNo comparisons at all. Count how many times each value appears, then write the values back from smallest to largest.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Counting sortSort by the ones digit, then by the tens digit, keeping ties in their previous order. After the last digit the whole array is sorted, without comparing two values.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Radix sort (LSD)Check every value from left to right until you find the target or run out of values.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Linear searchOn a sorted array, jump ahead √n values at a time until you pass the target, then walk back through that one block with a linear scan.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Jump searchOn a sorted array, look at the middle value. If it is too small, throw away the left half. If too big, throw away the right half.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Binary searchWalk the list once. At each node, save next, point the node back to prev, then move prev and curr one step forward.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Reverse a linked listslow moves 1 step, fast moves 2. With a cycle, fast laps slow and they meet. Without one, fast reaches null.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Floyd's cycle detectionMove fast n + 1 steps ahead of slow. Then move both until fast falls off the end: slow now sits just before the node to remove.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Remove the Nth node from the endPush every opening bracket. A closing bracket must match the top of the stack. At the end, the stack must be empty.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Stack: valid parenthesesStart at the root. Go left if the new value is smaller, right if bigger, until you reach an empty spot.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: BST insertEach comparison throws away one whole subtree, so a balanced tree is searched in O(log n) steps.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: BST searchFind the node. With zero or one child, its child takes its place. With two children, copy in the smallest value from the right subtree, then delete that one.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: BST deleteLeft subtree, then the node, then the right subtree.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Inorder traversalThe node first, then its left subtree, then its right subtree.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Preorder traversalBoth subtrees first, the node last.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Postorder traversalVisit the tree one level at a time from top to bottom, using a queue.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Level-order traversalThe depth of an empty tree is 0. Otherwise it is 1 plus the deeper of the two subtrees. Each node waits for both children, then reports up.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Maximum depth of a treeIf p and q are both smaller than the node, the answer is on the left. Both bigger, on the right. Otherwise they split here (or one of them is this node): this node is the answer.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Lowest common ancestor in a BSTAdd the new value at the end of the array, then let it bubble up while it is smaller than its parent.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Min-heap insertThe minimum is always the root. Remove it, move the last value to the root, and let it sink down to the smaller child until the heap is valid.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Min-heap extractA BST that keeps itself balanced. After each insert, if one side becomes more than 1 level taller, rotate to fix it.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: AVL tree insertEach edge is one letter. Words that share a prefix share the same path. A double ring marks where a full word ends.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Trie (prefix tree)Visit the start, then all its neighbors, then their neighbors. A queue keeps nodes in the order they were found.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Breadth-first searchGo as deep as possible along one path, then back up and try the next branch. The call stack remembers where to return.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Depth-first searchAlways finalize the closest unfinished node next, then try to improve the distance to each of its neighbors.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Dijkstra's shortest pathRelax every edge, V − 1 times. After round i, every shortest path that uses at most i edges is correct. One more round that still improves something means a negative cycle.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Bellman-Ford shortest pathAllow one more node k as a stopover at a time. For every pair (i, j), going i → k → j might beat the best path found so far. After every k has been tried, all distances are final.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Floyd-Warshall all-pairs shortest pathsCount incoming edges (in-degree). Nodes with in-degree 0 can go first. Removing them frees up more nodes.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Topological sort (Kahn)Every set is a tree; its root names the set. find walks up to the root. union points one root at the other. If both ends of an edge already share a root, that edge closes a cycle.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Union-Find (disjoint sets)Sort edges by weight. Take each edge unless its two ends are already connected. Union-find answers "already connected?" almost instantly.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Kruskal's minimum spanning treeGrow one tree from A. Always add the cheapest edge that reaches a node not yet in the tree.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Prim's minimum spanning treeScan every cell. Each time you land on unvisited land, that is a new island: count it, then sink the whole island with DFS so it is never counted again.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Number of islands (flood fill)Keep one running sum. When the window slides right, add the value coming in and subtract the value going out.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Sliding window (fixed size)Grow the window with r until it meets the condition, then shrink it with l as far as it stays valid.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Sliding window (variable size)Start at both ends. If the sum is too small, move the left pointer right. If too big, move the right pointer left.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Two pointers (opposite ends)Start with the widest container. Always move the shorter wall inward, because the taller wall can never do better with less width.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Container with most waterWater above a bar = the lower of (tallest wall on its left, tallest wall on its right) minus the bar. Two pointers find this without extra arrays.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Trapping rain waterfast reads every value. slow marks where the next kept value should go.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Fast and slow pointersAt each value, either extend the current subarray or start fresh here, whichever is bigger. Remember the best you have seen.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Kadane's algorithmIf prefix[j] = prefix[i] − k, the values between j and i sum to k. A hash map remembers how often each prefix sum appeared.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Prefix sum + hash mapThe stack holds values still waiting for an answer. A bigger value pops everything smaller than it and becomes their answer.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Monotonic stacklo marks where the next 0 goes, hi where the next 2 goes. mid scans the unknown part in between.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Dutch national flagPair every vote for the candidate with a vote against it, and cancel them. Whatever survives all the cancelling must be the majority, because it has more votes than everything else combined.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Boyer-Moore majority votehash(key) mod m picks a bucket. Keys that land in the same bucket (a collision) are kept in a short list. Lookup only scans one bucket.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Hash table with chainingWalk once. For each value, ask the hash map whether its partner (target − value) was already seen. If not, remember this value and its index.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Two Sum with a hash mapGrow the window to the right one letter at a time. A hash map remembers where each letter was last seen; on a repeat inside the window, jump the left edge just past that earlier copy.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Longest substring without repeatsFill a table from the smallest case up. Each cell reuses cells you already filled, so nothing is computed twice.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: 1D DP: climbing stairsbest[i] is the most money from the first i houses. Either skip house i (keep best[i − 1]) or rob it and add it to best[i − 2]. Take the bigger one.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: 1D DP: house robberdp[i] is the fewest coins for amount i. For each coin c, amount i can be reached from i − c with one more coin.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: 1D DP: coin changedp[i] is the length of the longest increasing run that ends exactly at a[i]. Look back at every j < i with a smaller value and extend the best one.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: 1D DP: longest increasing subsequenceYou can only enter a cell from above or from the left, so paths(r, c) = paths(r − 1, c) + paths(r, c − 1). An obstacle has 0 paths through it.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: 2D DP: unique paths with obstaclesdp[i][w] is the best value using the first i items with capacity w. Either skip item i (cell above) or take it (value + the cell up and to the left).
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: 2D DP: 0/1 knapsackdp[i][j] is the LCS of the first i letters of A and the first j letters of B. A match adds 1 to the diagonal. Otherwise take the bigger of up and left.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: 2D DP: longest common subsequencedp[i][j] is the cost to turn the first i letters of A into the first j letters of B. Same letter: copy the diagonal. Otherwise 1 + the cheapest of replace (diagonal), delete (up) or insert (left).
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: 2D DP: edit distanceFor each value, make a choice: include it or skip it. Go deeper, then undo the choice and try the other branch.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Backtracking: subsetsFill the answer one position at a time. At each position try every value not used yet, go deeper, then give the value back so the next branch can use it.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Backtracking: permutationsPlace one queen per row. Try each column. If it is safe, move to the next row. If no column works, backtrack and move the previous queen.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Backtracking: N-QueensWalk left to right and keep far, the furthest index reachable so far. If you ever stand on an index beyond far, you are stuck. If far reaches the end, you win.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Jump gameSort by end time. Keep an interval if it starts at or after the end of the last one kept. Finishing as early as possible leaves the most room for everything after.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Interval scheduling (non-overlapping)Subtracting 1 flips the lowest 1 bit to 0 and every 0 below it to 1. So n & (n − 1) erases exactly the lowest 1 bit. Count how many times you can do that before n is 0.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Count set bits (Kernighan)XOR is 1 where two bits differ. x ^ x = 0 and x ^ 0 = x, and the order does not matter. So XOR everything: each pair cancels itself, and only the single value is left.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Single number with XORCount mask from 0 to 2ⁿ − 1. Bit i of the mask says whether value i is in the subset. Counting in binary therefore lists every subset exactly once.
Class 11–12 · College & beyondLesson in Algo Simulator
Open lesson: Subsets with a bitmask
Orbit a full web backend and watch requests hit the CDN, load balancer, cache, replicas and workers.
College & beyondLesson in System Design Simulator
Open lesson: 3D architectureTurn daily users into requests per second, storage, bandwidth and a server count, with every step shown.
College & beyondLesson in System Design Simulator
Open lesson: Capacity planningDNS, TCP, TLS and HTTP packet by packet. Compare HTTP/1.1, HTTP/2 and HTTP/3 across the world.
College & beyondLesson in System Design Simulator
Open lesson: NetworkingRound robin vs least connections, health checks, crashes, traffic spikes and auto-scaling.
College & beyondLesson in System Design Simulator
Open lesson: Load balancingCache-aside with Redis: hit rate, TTL, cold starts and what happens to the database without it.
College & beyondLesson in System Design Simulator
Open lesson: CachingLRU, LFU, FIFO and Random race on the same traffic. Scans and shifting trends pick the winner.
College & beyondLesson in System Design Simulator
Open lesson: Cache evictionHash mod N vs consistent hashing, keys that move, and why virtual nodes even out the load.
College & beyondLesson in System Design Simulator
Open lesson: ShardingPick N, W and R. Watch stale reads appear and vanish, and what a failed replica does to availability.
College & beyondLesson in System Design Simulator
Open lesson: ReplicationBacklog, consumer capacity, retries and dead letters. See why queues absorb bursts but not overload.
College & beyondLesson in System Design Simulator
Open lesson: QueuesPartitions, keys, consumer groups, lag, rebalancing and replay, in seven guided steps.
College & beyondLesson in System Design Simulator
Open lesson: KafkaFour ways to push updates to a browser, on the same events: delay, requests and connections compared.
College & beyondLesson in System Design Simulator
Open lesson: Real-time updatesRouting, TLS, JWT auth, rate limits, caching and failover, with a live nginx.conf you can copy.
College & beyondLesson in System Design Simulator
Open lesson: API gatewayToken bucket, fixed window and sliding window under steady, bursty and window-edge traffic.
College & beyondLesson in System Design Simulator
Open lesson: Rate limitingWatch retries turn a slow dependency into a retry storm, and a circuit breaker stop it.
College & beyondLesson in System Design Simulator
Open lesson: ResilienceWatch sorting, searching, trees, heaps and graph algorithms run one step at a time, with animated visuals you can pause and replay.
Class 11–12 · College & beyondClass 11–12 Computer Science: searching, sorting and stacks
Launch simulator: Algo SimulatorBuild architectures from load balancers, caches, queues and databases, then watch traffic flow and see where they break.
College & beyondSoftware engineering: system design
Launch simulator: System Design Simulator
Follow a card transaction from the terminal through the payment switch to the issuing bank and back, including ISO 8583 messages and NCMC.
College & beyondPayments and banking systems
Launch simulator: Card Payment Switch Simulator
Build atoms by adding protons, neutrons and electrons, and see how the element, charge and isotope change.
Class 9–10 · Class 11–12Class 9 Science: Structure of the Atom; Class 11 Chemistry: Structure of Atom
Launch simulator: Atom Lab
Launch a projectile, change angle, speed, gravity, height and air drag, and compare trajectories, range and flight time.
Class 11–12Class 11 Physics: Motion in a Plane
Launch simulator: Projectile Motion
Swing a simple pendulum, change length, gravity, amplitude and damping, and compare the measured period with the small-angle formula.
Class 6–8 · Class 11–12Class 7 Science: measurement of time and motion; Class 11 Physics: Oscillations
Launch simulator: Pendulum
Oscillate a mass on a spring, change mass, stiffness and damping, and watch kinetic, elastic and lost energy trade places.
Class 11–12Class 11 Physics: Oscillations
Launch simulator: Spring and Mass
Collide two carts on a track, change their masses, velocities and restitution, and check momentum and kinetic energy before and after.
Class 9–10 · Class 11–12Class 9 Science: Force and Laws of Motion (momentum); Class 11 Physics: Work, Energy and Power
Launch simulator: Collisions
Put a block on a ramp, change slope, mass and friction, resolve the forces and predict whether it slides.
Class 11–12Class 11 Physics: Laws of Motion (friction, resolving forces)
Launch simulator: Inclined Plane
Spin an object around a circle, change radius, speed and mass, and inspect centripetal acceleration, force and what happens when the string is cut.
Class 11–12Class 11 Physics: Motion in a Plane; Laws of Motion
Launch simulator: Circular Motion
Launch a satellite around a planet, change its starting speed and direction, and compare circular, elliptical and escape trajectories.
Class 9–10 · Class 11–12Class 9 Science: Gravitation; Class 11 Physics: Gravitation
Launch simulator: Orbital Motion
Add two travelling waves, change their amplitude, frequency and phase, and watch superposition create constructive, destructive interference and beats.
Class 11–12Class 12 Physics: Wave Optics
Launch simulator: Wave Interference
Drive a string fixed at both ends, change length, tension, density and frequency, and find the resonant harmonics.
Class 11–12Class 11 Physics: Waves
Launch simulator: Standing Waves
Move a sound source and a listener, watch wavefronts bunch up and spread out, and compare emitted and received frequency.
Class 11–12 · College & beyondClass 11 Physics: Waves
Launch simulator: Doppler Effect
Drag an object in front of a thin lens, change the focal length, and trace the principal rays to find the image position, size and type.
Class 9–10 · Class 11–12Class 10 Science: Light – Reflection and Refraction; Class 12 Physics: Ray Optics
Launch simulator: Geometric Optics
Shine a ray between two media, change refractive indices and incidence angle, and find the critical angle and total internal reflection.
Class 9–10 · Class 11–12Class 10 Science: Light – Reflection and Refraction; Class 12 Physics: Ray Optics
Launch simulator: Refraction
Heat a metal rod, choose the material and end temperatures, and watch the temperature profile relax towards a straight-line steady state.
Class 6–8 · Class 11–12Class 7 Science: heat and conduction; Class 11 Physics: Thermal Properties of Matter
Launch simulator: Heat Diffusion
Squeeze, heat and fill a piston of bouncing particles, hold one quantity constant, and see Boyle's, Charles's and Gay-Lussac's laws emerge.
Class 11–12Class 11 Physics: Kinetic Theory (gas laws)
Launch simulator: Gas Laws
Place and drag positive and negative charges, and visualise the electric field vectors, field lines and equipotential contours they create.
Class 11–12Class 12 Physics: Electric Charges and Fields
Launch simulator: Electric Fields
Charge and discharge a capacitor through a resistor, change R, C and the supply voltage, and read the time constant from the exponential curves.
Class 11–12 · College & beyondClass 12 Physics: Electrostatic Potential and Capacitance
Launch simulator: RC Circuit
Drive a series RLC circuit with an AC source, sweep the frequency, and inspect current amplitude, phase and the sharpness of resonance.
Class 11–12 · College & beyondClass 12 Physics: Alternating Current (resonance)
Launch simulator: RLC Resonance
Push a bar magnet through a coil, change speed, turns and magnet strength, and connect the changing magnetic flux to the induced voltage.
Class 11–12Class 12 Physics: Electromagnetic Induction
Launch simulator: Electromagnetic Induction
Push water through a pipe that narrows and widens, change areas and flow rate, and compare speed and idealised pressure along the pipe.
Class 11–12Class 11 Physics: Mechanical Properties of Fluids
Launch simulator: Fluid Continuity
Drop blocks of different densities into different liquids, predict whether they float and how deep, and see Archimedes' principle balance the forces.
Class 9–10 · Class 11–12Class 9 Science: Gravitation (thrust, buoyancy, Archimedes' principle); Class 11 Physics: Fluids
Launch simulator: Buoyancy
Run a reaction A + B → C, change temperature, concentration and activation energy, and compare particle collisions with the rate law and Arrhenius equation.
Class 11–12Class 12 Chemistry: Chemical Kinetics
Launch simulator: Reaction Rates
Run a reversible reaction A ⇌ B to equilibrium, then add reactant, remove product or change temperature, and watch Le Chatelier's principle at work.
Class 11–12Class 11 Chemistry: Equilibrium
Launch simulator: Chemical Equilibrium
Add base from a burette to an acid, graph the pH curve, and identify the equivalence point, buffer region and a suitable indicator.
Class 9–10 · Class 11–12Class 10 Science: Acids, Bases and Salts; Class 11 Chemistry: Equilibrium (ionic)
Launch simulator: Acid–Base Titration
Release two gases on either side of a barrier, change temperature and particle count, and compare mixing with random-walk displacement statistics.
Class 6–8 · Class 9–10Class 9 Science: Matter in Our Surroundings (diffusion)
Launch simulator: Molecular Diffusion
Build a galvanic cell from two half-cells, find the anode, follow electron and ion flow, and work out the voltage with the Nernst equation.
Class 11–12Class 12 Chemistry: Electrochemistry
Launch simulator: Electrochemical Cell
Spot a mixture on a strip, change each dye's affinity and the solvent flow, and watch components separate by retention factor.
Class 6–8 · Class 9–10 · Class 11–12Class 6 Science: separating substances; Class 11 Chemistry: methods of purification
Launch simulator: Chromatography
Watch a sample of unstable nuclei decay at random, change half-life and starting count, and compare the stochastic count with the exponential expectation.
Class 11–12 · College & beyondClass 12 Physics: Nuclei
Launch simulator: Radioactive Decay
Drop a hot metal into water in an insulated cup, change masses, materials and temperatures, and solve the energy balance for the final temperature.
Class 11–12Class 11 Physics: Thermal Properties of Matter; Class 11 Chemistry: Thermodynamics
Launch simulator: Calorimetry
Dissolve salts in water, change temperature and amount, and see when a solution becomes saturated and excess solid remains or crystallises out.
Class 9–10 · Class 11–12Class 9 Science: Is Matter Around Us Pure (solutions); Class 12 Chemistry: Solutions
Launch simulator: Solubility
Move a sample of water or carbon dioxide around its pressure–temperature phase diagram and see where it is solid, liquid, gas or supercritical.
Class 11–12 · College & beyondExtends Class 9 states of matter; phase diagrams are college level
Launch simulator: Phase Diagram
Evolve a population of moths on light and dark bark, change the selection pressure and mutation rate, and track trait frequencies across generations.
Class 11–12Class 12 Biology: Evolution
Launch simulator: Natural Selection
Choose parental alleles for one or two genes, build the Punnett square, and compare expected offspring ratios with a random sample of offspring.
Class 9–10 · Class 11–12Class 10 Science: Heredity; Class 12 Biology: Principles of Inheritance and Variation
Launch simulator: Genetic Crosses
Model rabbits and foxes with the Lotka–Volterra equations, change growth and predation rates, and inspect population cycles and the phase-plane orbit.
Class 11–12 · College & beyondClass 12 Biology: Organisms and Populations (population interactions)
Launch simulator: Predator and Prey
Run the SIR model of an epidemic, change transmission, recovery and vaccination, and compare peak size, timing and final outbreak size.
Class 11–12 · College & beyondClass 12 Biology: Human Health and Disease; the SIR model is college level
Launch simulator: Epidemic Dynamics
Change substrate concentration, Vmax, Km and inhibitor type, and read reaction velocity curves and Lineweaver–Burk plots.
Class 11–12 · College & beyondClass 11 Biology: Biomolecules (enzymes)
Launch simulator: Enzyme Kinetics
Stimulate a model neuron, change stimulus strength and membrane properties, and watch threshold, action potentials, refractory periods and firing rate.
Class 9–10 · Class 11–12 · College & beyondClass 10 Science: Control and Coordination; Class 11 Biology: Neural Control and Coordination
Launch simulator: Neuron Signals
Separate two solutions with a semi-permeable membrane, change concentrations and permeability, and watch net water movement and osmotic pressure.
Class 9–10 · Class 11–12Class 9 Science: The Fundamental Unit of Life (osmosis); Class 12 Chemistry: Solutions (osmotic pressure)
Launch simulator: Osmosis
Adjust light intensity, carbon dioxide and temperature for a leaf, and explore which factor limits the rate of photosynthesis.
Class 6–8 · Class 9–10 · Class 11–12Class 7 Science: nutrition in plants; Class 10 Science: Life Processes; Class 11 Biology: Photosynthesis in Higher Plants
Launch simulator: Photosynthesis
Change species populations in a small grassland food web and follow how a change in one species ripples through the others.
Class 6–8 · Class 9–10 · Class 11–12Class 10 Science: Our Environment (food chains and webs); Class 12 Biology: Ecosystem
Launch simulator: Food Web
Run many populations at once under pure chance (Wright–Fisher model), change population size, and compare how fast alleles fix or vanish.
Class 11–12 · College & beyondClass 12 Biology: Evolution (Hardy–Weinberg, genetic drift)
Launch simulator: Genetic Drift
Move a point along a curve and shrink the secant interval to see the secant slope approach the derivative, with the derivative curve traced live.
Class 11–12Class 11 Maths: Limits and Derivatives; Class 12 Maths: Application of Derivatives
Launch simulator: Derivative Explorer
Approximate the area under a curve with left, right, midpoint and trapezoid sums, change partitions and bounds, and watch the error shrink.
Class 11–12Class 12 Maths: Integrals; Application of Integrals
Launch simulator: Integral Explorer
Build square, sawtooth and triangle waves by adding sine harmonics, inspect the spectrum, and see the Gibbs overshoot at jumps.
College & beyondFourier series: college mathematics and engineering
Launch simulator: Fourier Synthesis
Edit a 2×2 matrix and watch it transform a grid, the basis vectors and a shape, with determinant, eigenvectors and animation from the identity.
Class 11–12 · College & beyondClass 12 Maths: Matrices
Launch simulator: Linear Transformations
Drag two complex numbers on the Argand plane and see addition as vector sum, multiplication as rotate-and-scale, and powers and roots as spirals.
Class 11–12Class 11 Maths: Complex Numbers
Launch simulator: Complex Plane
Roll down a loss landscape with gradient descent, change the learning rate, start point and momentum, and see convergence, oscillation and divergence.
Class 11–12 · College & beyondBuilds on Class 12 Maths: Application of Derivatives (maxima and minima)
Launch simulator: Gradient Descent
Pick a distribution, change its parameters, draw random samples and compare the histogram with the theoretical curve, mean and spread.
Class 11–12 · College & beyondClass 12 Maths: Probability
Launch simulator: Probability Distributions
Take repeated samples from skewed or lumpy distributions, plot the sample means, and watch them form a normal curve as the sample size grows.
College & beyondCollege statistics
Launch simulator: Central Limit Theorem
Set a prior, observe evidence such as test results or coin flips, and watch the posterior probability update with Bayes' theorem.
Class 11–12 · College & beyondClass 12 Maths: Probability (Bayes' theorem)
Launch simulator: Bayesian Updating
Throw random points to estimate π or the area under a curve, and watch the error shrink with the square root of the sample count.
Class 9–10 · Class 11–12Class 10 Maths: Probability (estimating π with random points)
Launch simulator: Monte Carlo Estimation
Add, drag and delete data points and watch the least-squares line, residuals, R² and the pull of outliers update live.
Class 11–12 · College & beyondClass 11 Economics: Statistics for Economics (correlation); regression is college level
Launch simulator: Regression
Simulate thousands of experiments, change effect size, sample size and significance level, and measure false positives, power and p-values.
College & beyondCollege statistics
Launch simulator: Hypothesis Testing
Edit transition probabilities between weather states, simulate a random walk through the chain, and compare visit frequencies with the stationary distribution.
College & beyondCollege probability
Launch simulator: Markov Chains
Draw cells on a grid, set birth and survival rules, and watch Conway's Game of Life and other automata produce gliders, oscillators and chaos.
College & beyondBeyond the syllabus: complex systems
Launch simulator: Cellular Automata
Explore the Mandelbrot set, Julia sets, the Koch snowflake and a fractal tree, changing iteration depth and parameters to see self-similar detail.
Class 11–12 · College & beyondBuilds on Class 11 Maths: Complex Numbers
Launch simulator: Fractals
Tune separation, alignment and cohesion for a flock of boids and watch coordinated flocking emerge from simple local rules, with a predator option.
College & beyondBeyond the syllabus: complex systems
Launch simulator: Flocking
Generate a toy RSA key from two primes, encrypt and decrypt a message step by step, sign it, and see why factoring the modulus breaks the key.
Class 11–12 · College & beyondBuilds on Class 10 Maths: Real Numbers (primes); Class 11 Computer Science: cyber safety
Launch simulator: RSA Cryptography
Insert keys into a hash table, compare chaining, linear and quadratic probing, and measure collisions and probes as the load factor grows.
College & beyondCollege data structures
Launch simulator: Hash Tables
Place current-carrying wires and coils, and see the magnetic field lines, strength and direction they create, plus forces between parallel wires.
Class 9–10 · Class 11–12Class 10 Science: Magnetic Effects of Electric Current; Class 12 Physics: Moving Charges and Magnetism
Launch simulator: Magnetic Fields
Edit process arrival and burst times, then compare FCFS, SJF, SRTF, priority and round-robin schedules on a Gantt chart with waiting and turnaround times.
College & beyondCollege operating systems
Launch simulator: CPU Scheduling
Run a page reference string through FIFO, LRU, Optimal and Clock, change the frame count, and compare page faults, including Bélády's anomaly.
College & beyondCollege operating systems
Launch simulator: Page Replacement
Send addresses through direct-mapped, set-associative and fully associative caches, see tag, index and offset bits, and compare hit rates.
College & beyondCollege computer organisation
Launch simulator: Cache Mapping
Assign resources to processes, draw the resource-allocation graph, detect cycles, and run the Banker's algorithm to find safe sequences.
College & beyondCollege operating systems
Launch simulator: Deadlock
Compare a full table scan with a B-tree index lookup on generated data, change table size and query selectivity, and count the rows and pages each one touches.
Class 11–12 · College & beyondClass 12 Computer Science: Database Concepts and SQL
Launch simulator: Database Indexes
Interleave two database transactions under different isolation levels and watch dirty reads, lost updates and write skew appear or get blocked.
College & beyondCollege databases
Launch simulator: Transaction Isolation
Build an object graph with roots and references, drop roots, and watch mark-and-sweep and reference counting find garbage, including leaked cycles.
College & beyondCollege programming languages
Launch simulator: Garbage Collection
Type an arithmetic expression and follow it through tokenising, parsing into a syntax tree, stack-machine code and evaluation.
College & beyondCollege compilers
Launch simulator: Compiler Pipeline
Toggle inputs on digital circuits from single gates to a half adder, full adder and SR latch, trace signal propagation, and generate truth tables.
Class 11–12 · College & beyondClass 11 Computer Science: Computer Systems (Boolean logic)
Launch simulator: Logic Gates
Step a deterministic finite automaton through an input string, edit its transitions, and see which strings it accepts, from binary divisibility to turnstiles.
College & beyondCollege theory of computation
Launch simulator: Finite State Machines
Encode 4 data bits with Hamming(7,4), flip bits in transit, compute the syndrome, and see single errors corrected and the limits when two bits flip.
College & beyondCollege networks and coding theory
Launch simulator: Error-Correcting Codes
Simulate random arrivals at one or more servers, change arrival and service rates, and compare queue length and waiting time with M/M/c theory.
College & beyondCollege operations research
Launch simulator: Queueing Systems
Run a shop's stock day by day with random demand, set the reorder point, order size and lead time, and compare stockouts and costs.
College & beyondCollege operations management
Launch simulator: Inventory Control
Run a four-stage supply chain, change demand and delays, and watch small changes in customer demand grow into the bullwhip effect.
College & beyondCollege operations management
Launch simulator: Supply Chain
Simulate a serial production line, change station times, variability and buffer sizes, and find the bottleneck that sets throughput.
College & beyondCollege operations management
Launch simulator: Assembly Line
Time a two-phase traffic signal, change green times and arrival rates, and compare measured queues and delay with Webster's formula.
College & beyondCollege transport engineering
Launch simulator: Traffic Signals
Run a lift in a ten-floor building, add calls, and compare first-come-first-served, nearest-stop and sweep scheduling on waiting time and fairness.
College & beyondCollege operations research
Launch simulator: Elevator Dispatch
Place items to pick in a six-aisle warehouse and compare the walking distance of return, S-shape, nearest-neighbour and optimal picking routes.
College & beyondCollege operations research
Launch simulator: Warehouse Picking
Edit task durations and dependencies in a building project and watch the critical path method find the project length and each task's slack.
College & beyondCollege project management
Launch simulator: Project Scheduling
Compare who wins and what they pay in first-price, second-price, English and Dutch auctions, and test revenue equivalence over many random auctions.
College & beyondCollege economics
Launch simulator: Auction Mechanisms
Shift supply and demand curves, add a tax, price ceiling, floor or quota, and see the equilibrium, consumer and producer surplus, and deadweight loss.
Class 11–12 · College & beyondClass 12 Economics: Introductory Microeconomics (demand, supply, market equilibrium)
Launch simulator: Market Supply and Demand
Change latitude, date, time, panel tilt and direction, and see the sun's path, the angle sunlight hits the panel, and daily energy.
Class 6–8 · Class 11–12Class 6 Social Science: Earth's motions and seasons; Class 11 Geography: Solar Radiation, Heat Balance and Temperature
Launch simulator: Solar Panel Geometry
Change wind speed, rotor size, air density and control, and explore turbine power with the cube law, the Betz limit and tip-speed ratio.
Class 9–10 · College & beyondBuilds on Class 9 Science: Work and Energy (kinetic energy)
Launch simulator: Wind Turbine
Size an off-grid solar battery system, set load and generation profiles, and track state of charge, unmet demand and spilled energy hour by hour.
Class 11–12 · College & beyondBuilds on Class 12 Chemistry: Electrochemistry (batteries)
Launch simulator: Battery Storage
Trip a power station or add load, and watch the grid's frequency fall and recover through inertia, governor droop and automatic control.
College & beyondCollege power systems
Launch simulator: Grid Frequency
Choose insulation, glazing and air-tightness for a two-storey house and compare U-values, the temperature through the wall and heat loss.
Class 11–12 · College & beyondClass 11 Physics: Thermal Properties of Matter (conduction)
Launch simulator: Building Insulation
Set rainfall pattern, roof size, tank capacity and daily use, then run a year of daily water balance and track tank level, overflow and shortages.
Class 6–8 · Class 9–10Class 10 Geography: Water Resources (rainwater harvesting)
Launch simulator: Rainwater Harvesting
Change storm size and land cover for a small catchment, and compare simplified runoff curves and flood hydrographs with the SCS curve number method.
Class 9–10 · College & beyondClass 10 Geography: Water Resources
Launch simulator: Watershed Runoff
Run a four-reservoir carbon cycle model from 1850 to 2200, change future emissions, and track atmospheric CO₂ and where the carbon goes.
Class 11–12 · College & beyondClass 11 Geography: World Climate and Climate Change
Launch simulator: Carbon Cycle
Change a city surface's colour, shade, vegetation and heat storage, and compare its energy balance and day–night temperatures with a park.
Class 11–12 · College & beyondClass 11 Geography: Solar Radiation, Heat Balance and Temperature
Launch simulator: Urban Heat
Follow 100 tonnes of packaging through collection, sorting and reprocessing, and see how much becomes new material over repeated cycles.
Class 6–8 · Class 9–10Class 10 Science: Our Environment (managing waste)
Launch simulator: Recycling Systems
Tune P, I and D gains on a mass–spring–damper, add disturbances and actuator limits, and see overshoot, settling time and steady-state error.
College & beyondCollege control engineering
Launch simulator: PID Control
Set joint angles or drag a target for a two-link robot arm, and explore forward and inverse kinematics, elbow-up and elbow-down, and reach.
Class 11–12 · College & beyondBuilds on Class 11 Maths: Trigonometric Functions
Launch simulator: Robot Arm
Change tooth counts in simple and compound gear trains, and inspect rotation direction, speed ratio and ideal output torque with animated meshing gears.
Class 6–8 · College & beyondBuilds on Class 6–8 Maths: ratio and proportion
Launch simulator: Gear Trains
Load simply supported or cantilever beams, change span, material and section, and see deflection, bending moment, shear and stress.
College & beyondCollege structural engineering
Launch simulator: Beam Deflection
Load Pratt, Howe, Warren and A-frame trusses, change span, height and loads, and see tension and compression in every member by the method of joints.
Class 11–12 · College & beyondBuilds on Class 11 Physics: Laws of Motion (equilibrium of forces)
Launch simulator: Truss Forces
Mount a machine on springs and dampers over a shaking floor, change mass, stiffness, damping and frequency, and compare transmissibility.
Class 11–12 · College & beyondClass 11 Physics: Oscillations (forced oscillations, resonance)
Launch simulator: Vibration Isolation
Change a signal's frequency and sampling rate, see aliasing, compare reconstructions, and see how quantization bits limit precision.
College & beyondCollege signals and systems
Launch simulator: Digital Sampling
Apply low-pass, high-pass, band-pass and notch filters, see the frequency response in decibels, and hear what they do to hum, a tone and hiss.
College & beyondCollege signals and systems
Launch simulator: Audio Filtering
Edit a 3 × 3 kernel and step through convolution pixel by pixel to see how blur, sharpening and edge detection transform a small test image.
College & beyondCollege image processing
Launch simulator: Image Convolution
Edit sample text, build its Huffman code tree, compare bit counts with plain and fixed-length codes and the entropy limit, and watch the bits decode one by one.
College & beyondCollege information theory
Launch simulator: Compression CodingTry a different word, or clear the filters.