🧠 Brainy

Physically modelled sea you can retune — wind speed, swell, choppiness — rendering waves that behave properly.

Tagged great whites ping their position whenever a fin breaks the surface, each shark named, weighed and given its own profile page.

An encyclopedia of the world's writing systems, including the invented, the extinct and the barely attested.

Where English words came from, sourced and dated, compiled by one man who has been at it since 2000.

The English-speaking world's Go server, where correspondence games run for weeks and somebody always explains why your move was bad.

A daily index of the free courses, audiobooks, films and ebooks scattered across the rest of the internet.

Scan a barcode and get ingredients, additives and a nutrition score from a database anyone can edit. Wikipedia for groceries.

Free, ad-free versions of the actual academic instruments, with the collected raw data published for anyone who wants to poke at it.

Open-source successor to Territorial.io: push borders across a world map, form alliances and break them at precisely the right moment.

Gallery of Processing and p5.js sketches where every piece runs in the page and the source is right there to fork.

Every railway line on Earth mapped with signalling, gauge, electrification and maximum speed, by people who care about this very deeply.

A research-grade open flight tracking network run by universities, with live maps and the raw historical data behind them.

Stanford's model of travel in the Roman world — pick two cities and get the cost, season and days by road or sea.

Oxford's open charts on poverty, energy, health and war, with the underlying data downloadable from every single one.

Write creative code in one pane and watch it run in the next, with no install, no build step and no configuration.

John McLeod's encyclopedia of card game rules, covering every regional variant of everything and settling every dispute.

Recorded user flows from real products, so you can watch an onboarding happen rather than guess at how it went.

The old-school colour scheme designer: one wheel, a live preview page, and far more control than the modern tools.

MIT's ranking of historically famous people by how many language editions of Wikipedia bother to carry them.

Drag mildly biased shapes around a grid and watch a segregated neighbourhood assemble itself without anyone intending it.

Historically accurate emulations of early PCs, down to the timing, with the original manuals and ROM listings alongside.

A database of essentially every named summit on Earth, with prominence figures, ascent logs and rankings that fuel very long arguments.

A crowd-voted encyclopaedia arguing over the MBTI and enneagram type of every fictional character and public figure in existence.

Proper trait questionnaires with the scoring shown, rather than a quiz that decides you are a golden retriever.

Sixteen questions sort you into one of Pew's nine American political groups, with a decade of real survey data behind every one.

Colorado's library of physics, chemistry and maths simulations, used in classrooms everywhere and free to meddle with.

Interactive tests designed to find the contradictions in your own stated beliefs, the classic being Battleground God.

Weather model charts for anywhere in the world, fast and free, of the sort forecasters look at rather than the tidied-up app version.

Names a pixel size and asks you to drag a box exactly that big. Nobody is as good at this as they assume.

Draw on the grid and it writes the box-shadow monstrosity that renders your sprite with no image file involved at all.

Two decades of the pixel art scene's best work, still curated by hand and still running weekly drawing challenges.

Every Poe story and poem with annotations, a timeline and a vocabulary tool, kept by one enthusiast since the early web.

A noughts-and-crosses grid where every square needs a Pokemon matching two criteria at once, scored on how obscure your picks were.

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

Twenty-five minute cycles with a running log of what you spent each one on, in case you need the evidence later.

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

A properly staffed magazine covering what is going right, funded by its readers rather than by outrage.

Threat-model-first advice from the community that succeeded PrivacyTools, so you pick tools for your actual risk rather than a vibe.

Britain's satirical fortnightly, half jokes and half genuine investigative reporting, in print since 1961.

A medieval life simulator where you idle through jobs and skills, die of old age, and are reborn with a small head start.

Harvard's implicit association tests, measuring the biases you would never report about yourself. Uncomfortable, rigorous and free.

The Vedic side of the practice: kundli, dasha periods and panchang, calculated free with the underlying reasoning shown.

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

The Only Connect connecting wall in thousands of user-made versions: sixteen clues, four groups, two and a half minutes.

Daily nonograms in every size from five squares to fifty, with a timer and no attempt whatsoever at decoration.

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.

Zach Gage's daily puzzle collection — Cross|word, Flipart, Really Bad Chess — with the best interface in the genre by a distance.