Compendiums Interactive explainers and simulations
Interactive explainers and simulations
Simulations and explanations that run in a browser, where you change a value and watch what follows, grouped by subject. Kosplora’s own are on its simulations page.
35 resources, read at their own pages, most recently on 2026-10-21. Licences are given as each page states them. Links last checked 2026-10-23, all reached.
Physics
Bartosz Ciechanowski's articles
Bartosz Ciechanowski
Read long articles on how the Moon, airfoils, bicycles, sound, GPS and mechanical watches work, with interactive figures throughout.
Circuit Simulator
Paul Falstad and Iain Sharp
Build or load an electronic circuit and watch voltages and moving current dots as switches are flipped and components edited.
Math, Physics, and Engineering Applets
Paul Falstad
Open browser simulations of waves, acoustics, electromagnetism, quantum mechanics, thermodynamics and vector calculus, most now converted from Java to JavaScript.
myPhysicsLab
Erik Neumann
Run about 50 mechanics simulations, including springs, chaotic pendulums, rigid-body collisions and roller coasters, and change their parameters.
PhET Interactive Simulations
University of Colorado Boulder
Run HTML5 simulations of physics, chemistry, biology, earth science and maths topics in the browser and change their settings to test ideas.
Chemistry
ChemCollective Virtual Lab
ChemCollective, Carnegie Mellon University
Pick from hundreds of aqueous reagents and mix and measure them in a virtual stockroom to work problems on molarity, titration, equilibrium, solubility and redox.
ChemTube3D
Nick Greeves, University of Liverpool
Rotate 3D animations of organic reaction mechanisms, inorganic and solid-state structures and bonding for school and university chemistry.
Biology
HHMI BioInteractive
Howard Hughes Medical Institute
Use biology interactives, animations and virtual labs on topics from cell biology and genetics to ecology and evolution.
Learn.Genetics Virtual Labs
Genetic Science Learning Center, University of Utah
Carry out simulated DNA extraction, gel electrophoresis, PCR, flow cytometry and DNA microarray experiments step by step.
NetLogo Web
Center for Connected Learning, Northwestern University
Open agent-based models from the NetLogo Models Library in the browser and run them, upload a model, or start one from a blank page.
What Happens Next? COVID-19 Futures
Marcel Salathé and Nicky Case
Play epidemic models (SIR, SEIR, SEIRS), change R0 and recovery time, and test lockdowns, contact tracing, masks and vaccination in a sandbox.
Earth and climate
En-ROADS
Climate Interactive and MIT Sloan
Move policy and technology sliders in a climate simulator and see how global temperature, energy use and other outcomes change.
Eyes on the Solar System and other Eyes apps
NASA
Fly through 3D browser views of the solar system, asteroids, Earth and exoplanets built from NASA data.
STEM Resource Finder
The Concord Consortium
Search free simulations and activities by subject and grade, covering chemistry, earth and space, physics, life science, data science and more.
Mathematics
An Interactive Introduction to Fourier Transforms
Jez Swanson
Draw a wave or shape and watch it rebuilt from sine waves and rotating circles, then see how JPEG compression uses the same idea.
Desmos
Desmos Studio PBC
Plot functions and data, add sliders and watch graphs change in the graphing calculator and the other free calculators.
Explained Visually
Victor Powell and Lewis Lehe
Manipulate short visual explainers on Markov chains, eigenvectors, principal component analysis, least squares regression, image kernels and conditional probability.
GeoGebra
GeoGebra
Use linked graphing, geometry, 3D and scientific calculators and open community-made interactive activities.
Immersive Linear Algebra
J. Ström, K. Åström and T. Akenine-Möller
Read a linear algebra textbook from vectors to eigenvalues with fully interactive figures.
Polypad
Amplify Education (from Mathigon)
Drag virtual manipulatives such as fraction bars, polyhedra, balance scales, dice and logic gates on an open canvas with no login.
Why Momentum Really Works
Gabriel Goh, Distill
Adjust step size and momentum in live plots to see how gradient descent with momentum converges or oscillates.
Statistics
R Psychologist interactive visualizations
Kristoffer Magnusson
Change sample sizes and effect sizes in simulations of p-values, statistical power, confidence intervals, Cohen's d, correlation and Bayesian inference.
Seeing Theory
Daniel Kunin and team, Brown University
Work through six interactive chapters, from basic probability and distributions to Bayesian inference and regression.
StatKey
Lock family, authors of Statistics: Unlocking the Power of Data
Run bootstrap confidence intervals, randomization tests and sampling distributions on built-in or their own data.
Computing
A Neural Network Playground
Daniel Smilkov and Shan Carter, Google
Train a small neural network in the browser and change layers, neurons, activation, learning rate and regularization while watching its output form.
NandGame
Olav Junker Kjær
Build a computer level by level, starting from relays and NAND gates and going on through adders, memory and a processor.
Red Blob Games
Amit Patel
Work through interactive tutorials on pathfinding, hexagonal grids, map generation from noise, visibility and line drawing.
Transformer Explainer
Polo Club of Data Science, Georgia Tech
Type text into a GPT-2 small model running in the browser and follow each step to the next-word prediction, changing temperature and sampling.
VisuAlgo
Steven Halim and students, National University of Singapore
Enter their own input and watch animations of 24 data structure and algorithm modules, then test themselves in a training quiz.
Economics
EconGraphs
Christopher Makler
Drag curves and points in interactive graphs on supply and demand, consumer and firm theory, market power, game theory and growth.
Society
Bad News
Tilt and the Cambridge Social Decision-Making Lab
Play a short game as a fake news producer chasing followers to learn the tactics used in misinformation, with an optional anonymous research questionnaire.
Going Critical
Kevin Simler
Pull sliders and run simulations of how infections, ideas and wildfires spread across networks.
Parable of the Polygons
Vi Hart and Nicky Case
Move shapes and adjust their bias in a segregation model and watch a graph of how small preferences produce a divided neighbourhood.
The Evolution of Trust
Nicky Case
Play through an interactive guide to the game theory of why and how people trust each other.
Art and music
The Book of Shaders
Patricio Gonzalez Vivo and Jen Lowe
Change fragment shader code in the page and see the image change, working from shaping functions to noise, patterns and simulation.