Feels like magic

Solitaire where you choose the shape of the tableau and the rules first, then discover whether it was ever solvable.

Age pyramids for any country from 1950 to 2100, which settles most demographic arguments in a single shape.

A twenty-year-old particle sandbox where wind, fire, magma and ice all interact, with thousands of saved player scenes.

The sequel, with proper solid objects and adjustable gravity, and a public save gallery going back well over a decade.

The RPG with the player removed: choose a race, then watch the bars fill for years. Still the sharpest joke about the genre.

The colour-word interference test as the real psychology experiment rather than a quiz-site imitation, with your data at the end.

Free monthly puzzle sets designed to be solved in a pub, with a decade of archives you can print at home.

A question site where people post original puzzles and strangers solve them properly, with the reasoning shown.

A quantum computing textbook with spaced repetition built into the page, so what you read has a chance of staying.

Doodle six things in twenty seconds while a neural net shouts guesses at you. The training set it produced now runs to fifty million drawings.

Crowd-sourced feed of well-made and gloriously pointless websites, and the closest thing left to a modern stumble button.

Photographs of corridors, swimming pools and hotel lobbies with nobody in them, which is far more affecting than that sounds.

Steady feed of new illusions with the comments doing the debunking, which is usually half of the entertainment.

Home of the shared pixel canvas where millions of people fought surprisingly politely over a few million squares.

Archive of the experiment where one button and one click each spawned genuine factions, martyrs and a working theology within days.

A community-maintained open database of internet radio streams with no company behind it, which is why the odd little stations survive there.

Spin a globe covered in green dots and drop the needle on a live local station anywhere on Earth. The buffering is part of the charm.

Pick a country and a decade on a world map and hear what people there were actually listening to, curated by humans since 1900.

One button, one random inhabited spot on Earth in Street View, most of them somewhere nobody would ever have chosen to look.

Blows one image up into a multi-page halftone poster that you print at home and tape across an entire wall.

A snarkier reference work covering pseudoscience, conspiracy theories and the people making a living from them.

Paste a spreadsheet, pick from chart types most tools refuse to offer, and export an editable vector file.

Amit Patel's tutorials on pathfinding, hexagonal grids and noise, with every parameter exposed as a slider you can ruin.

A Wikipedia article with every meaningful word blacked out; guess words to reveal them until you can name the subject.

Women's magazine parody with headlines observed so precisely that they read as criticism rather than jokes.

Wathan and Schoger's rules for making things look designed when you are not, in fact, a designer.

Rhymes, near rhymes, synonyms and usage examples — quietly the best tool available to anyone writing anything.

Roguelike tower defence where you lay the map down as you go, and every tile placed narrows the next decision.

Sandwiches rotating slowly on a loop, under a tagline that reads simply, and accurately, that's it.

Three colour fields flipping between red, green and blue as you move, a fixture of the useless-web canon and a strobe risk.

Run through a tunnel in space where the walls become the floor whenever you turn. An entire generation played this instead of maths.

The Cube Escape series in full and free — bleak Dutch point-and-click rooms with a lake, a lot of birds and a plot you assemble sideways.

Archive of notable animation cuts, tagged by the individual animator who drew them. Studying the craft one sequence at a time.

The first Samorost, free in the browser, a wordless point-and-click about a small gnome diverting a planet off a collision course.

A falling-sand game with several hundred materials that all react properly, including a dozen ways to end the world by mistake.

Falling-sand physics with fire, water, plants and lava, plus a public gallery of what everybody else set alight.

Tetris where the blocks collapse into falling sand, so a line only clears when one colour touches both walls. Fiendish and lovely.

Reverse image search tuned for illustration: hand it a cropped screenshot and it names the artist and the original post.

Conservation campaign for a cephalopod that lives in trees, used for over twenty years to teach children about checking sources.

Drag one slider from quantum foam to the cosmic web, with every object in between labelled at its true size.

Rough sketch in, finished image out, with the result following your actual lines rather than politely ignoring them.

Converts your scrolling into real distance and tells you what you have just passed — a giraffe, the Eiffel Tower, low Earth orbit.

The original semantic-distance guessing game, noticeably harder than its descendants and considerably more humbling.

Word association against a machine: type anything semantically close to the target and the block clears. Tetris rules, meaning as the mechanic.

Raw Sentinel and Landsat imagery for anywhere on the planet, free, with band combinations that reveal crops, floods and old burn scars.

Short visual explanations of statistics ideas — eigenvectors, conditional probability, Markov chains — all draggable.

Thousands of full-screen graphics experiments, each one a few hundred lines of maths you can read and edit live.

Drag the control points of a letter back into shape. Your score is how far off the real typeface you landed.