the playground

Free physics/chem/math sims from University of Colorado.

Circuit, wave, and vector field simulators.

Interactive science and physics simulations.

Absurdly deep interactive explainers — gears, cameras, GPS, lenses.

Thousands of interactive math and science demos.

Interactive models of complex systems — flocks, epidemics, sandpiles.

Free interactive book on simulating physics and life in code.

Real-time Kerr-metric black hole renderer — gravitational lensing you can fly around.

A huge free collection of interactive physics simulations, sim by sim.

Plot and animate math functions live, from simple curves to volumetric 3D.

Drop and layer colored sand — a slower, painterly cousin of the cellular-automaton toys.

Zoom from quarks to the observable universe.

Scroll a true-to-scale solar system.

Research and data on the world's biggest problems.

Hans Rosling's animated stats explorer.

Visual essays and data journalism.

Long-form deep dives that turn into full afternoons.

Data visualizations on everything.

Government data on America, sourced and visualized.

xkcd's absurd hypothetical questions, answered seriously.

Watch the internet happen in real time — users online, emails sent, sites created, all ticking up live.

Drag any country across the map and watch it warp — Mercator projection's lies, made obvious.

What every country makes, buys, and sells, visualized as trade flows you can actually explore.

Zoom into gigapixel Hubble and Gaia sky surveys from your browser.

Explore the Milky Way and beyond across the entire electromagnetic spectrum.

Every tracked near-Earth object, orbiting in real time.

Live positions of every planet, comet, and visible object overhead right now.

World population, births, deaths — all ticking up live in front of you.

Live radio stations worldwide, browse by location on a globe.

Live global wind and weather map.

Every undersea internet cable on Earth.

Live global ship tracking.

Live global flight tracking, open and unfiltered.

Live global wind, ocean current, and weather visualization.

Live webcams from thousands of places on Earth.

Watch 40 years of satellite imagery turn into a time-lapse of the whole planet.

Click the door, step through to a random real place via Street View — could be anywhere on Earth.

A genuinely full flight simulator running in your browser — pick a plane, pick an airport, take off.

Live satellite imagery of the whole planet — storms, wildfires, clouds moving in real time.

Real-time 3D positions of every planet, moon, and spacecraft NASA is currently tracking.

Fly out from the sun through a real, navigable 3D map of our galactic neighborhood.

One country silhouette a day — guess it in six tries, Wordle rules.

Real-time status of every dish talking to our deep space probes.

Browse the entire planet through actual satellite imagery, any day, any layer.

Every earthquake on the planet in the last hour, live.

Live solar flares, aurora forecasts, and the sun losing its mind.

A whole site of interactive toys and games.

Hub of interactive essays (Nicky Case et al).

Interactive essay on segregation and bias.

Random pointless website generator.

Falling-sand cellular automata playground.

The original rabbit hole, one click at a time.

AI-generated faces — refresh for a new one.

Watch someone else's window view, somewhere in the world.

An infinitely, seamlessly zooming painting.

Finds a photo of someone pointing at your cursor.

Generative art and animation, each demo written in 140 characters of JavaScript.

A WebGL portfolio site you drive a go-kart around. Just try it.

Google's AI tries to guess your doodle in real time. Weirdly addictive.

Race from one Wikipedia article to another using only blue links.

A digital playground running since 1999 — bouncy balls, planetariums, webcam toys, and more.

Draw with mirrored, flowing generative art — move your mouse, watch symmetry bloom.

One button, one random Wikipedia page. The purest rabbit hole there is.

One line of 1982 BASIC that draws an infinite maze — the whole history of generative art in a tweet.

Every version of almost every website, ever. Pick a date, pick a URL, see the dead internet.

The Internet Archive's search engine for GeoCities-era animated GIFs. Pure late-90s chaos.

You can't. Nobody can. Try anyway.

Every edit to Wikipedia, worldwide, as a chime.

Build a beat by dragging characters onto a stage.

Tap keys for instant animated sound and visuals.

An interactive map of every music genre there is.

Google's playful interactive music experiments.

Mix rain, wind and fire into your own ambient background noise.

A deceptively deep incremental game that starts with catnip and spirals from there.

An incremental game about an AI that really, really likes making paperclips.

Deep, fine-tunable ambient soundscapes — rain, cafés, engines, drones, and more.

The original incremental clicker. One cookie becomes a bakery empire. Beware.

Think of any character — real or fictional. The genie will guess it. He's unsettlingly good.

Answer trivia, donate rice to the UN World Food Programme per correct answer. Free, no catch.

Cats. Bouncing. To music. Click for more cats.

Test your reaction time, memory, and typing speed against everyone else who's tried.

Race strangers by typing quotes as fast as you can. Brutally competitive.