Every character is filed under one of 214 keys, and the keys are pictures: water, fire, a hand, a roof, a horse. Laid out by what they are about rather than by stroke count, they make a map of what mattered to the people who drew them — and a map is easier to remember than a list.
Mandarin and Cantonese share every key: the keys are a property of the written character, not of the language. What differs is the reading (pinyin against Jyutping — both are here) and, for twenty-one keys, the simplified shape the mainland writes against the traditional shape Hong Kong keeps. Switch on Traditional to see those.
Switch each layer on or off: the character, the traditional form, the Mandarin reading, the Cantonese reading, a translation in any language on the site, and an icon. Character off with the icon on is a quiz. Click a key for everything about it. A dotted line runs from a key to every other group it belongs to — 魚 is an animal, a food and the fishing one.
The grouping follows the poster A Radical View, and it is a reading, not a fact: 魚 is filed under animals first and linked to food and fishing, and another reader would file it the other way. The 31 keys with no meaning — the strokes and boxes that describe a character's shape — sit in their own faded cluster. Cantonese readings of the rare structural keys are the dictionary's; nobody says them aloud. Icons are emoji, so a few keys have the nearest picture rather than an exact one.