Ten minutes to kill

Rain radar for most of the world with a past-and-future loop, which answers the question of whether to leave now in about four seconds.

Half an hour of rain and distant thunder on a loop, running since before background noise was a productivity category.

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

Every train on the British network with the signalling data attached: which loop it was held in, where it lost four minutes and why.

Reaction time, visual memory, number span and typing speed, each scored against everyone else who has taken it.

Leaves a trail of emoji behind your cursor. There is nothing more to it than that, and nothing more is needed.

Cuts the background out of a photo in about five seconds, stray hairs included. Free at web resolution, no account needed.

Translations shown inside real bilingual sentences, so you can see which option a person would actually use.

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

A hundred yes-or-no questions about things you may have done, counted downward from 100. A student rite of passage since the 1980s.

Two-button duel on a rooftop where recoil, rather than aim, decides which of you falls off the building first.

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

The percentage that launched a thousand arguments — the share of critics who were positive, which is not an average score.

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

Tells you the best three minutes to leave for the toilet during any film, and summarises exactly what you missed. Absurd, and it works.

Live cameras on pandas, penguins, apes and elephants, with keepers wandering into shot at feeding time and narrating as they go.

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

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.

Find one to twenty-five scattered across a grid, in order, against the clock. The standard peripheral-vision and attention drill.

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

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

One piano, several people, one link — everybody's keys light up in a different colour and it descends into noise fast.

A first-person shooter in which every player is an egg and every hit is messy. Considerably better than that premise deserves.

A daily high-resolution photograph from the early twentieth century, usually with commenters identifying the buildings.

Ragdoll obstacle course whose entire design goal is taking your stickman apart in an inventive new way each level.

A live feed of OpenStreetMap edits as they happen, zooming to each contributor's patch of the world one small correction at a time.

A no-frills portal unusually strong on two-player games you can play on one keyboard with somebody sitting next to you.

Enter any two articles and get every shortest path of links between them, drawn as a graph you can drag.

Live HD cameras on piazzas, beaches and ski slopes across Europe and beyond, which is the closest a browser tab gets to a day trip.

The custom emoji every workplace eventually accumulates, downloadable as a pack. The party parrot is in there.

Grow a snake on glowing pellets and cut other players off so they burst into more of them. The .io boom started here.

Roll a ball down an endless neon slope at rising speed until the geometry wins, which it always eventually does.

Three-minute kart deathmatches with weapon crates and absolutely no patience for anything resembling a racing line.

The National Zoo's cameras on lions, elephants and naked mole rats, publicly funded and refreshingly free of any advertising.

An endless sheet of virtual bubble wrap that pops under the cursor and quietly refills itself behind you.

The original rumour desk, still patiently establishing whether the thing your uncle forwarded actually happened.

Two-legged football played with a single key, in which the physics engine scores most of the actual goals.

Klondike that loads in under a second, with nothing on the page except green baize and the cards.

Listener-funded, advert-free channels out of San Francisco, Drone Zone and Groove Salad among them, going since the dial-up era.

Grid sequencer with a marimba and a drum kit, tuned so that anything you tap sounds passable, then shared as a link.

The South Park character maker that has been running since 1999 and still gets updated with props from new episodes.

Ride a lift from the ground to geostationary orbit, passing every layer of atmosphere and satellite on the way.

The original film's promotional site, left online untouched for nearly thirty years and preserved when the sequel arrived.

Code typing drills across a dozen languages, where the indentation is handled for you and the punctuation certainly is not.

NASA's tracker for when the space station is visible from where you live, with sighting alerts by email.

Constructive journalism collected from other outlets into one free feed, so somebody else does all the sifting.