Water Sort is a sorting puzzle with a simple rule: you can pour from one tube into another only if the colours on top match, or the target tube is empty. Start with a rack of tubes holding jumbled layers of colour and finish with each tube holding one colour and nothing else.
There's no timer and no score — just the puzzle, and the moment where you realise you've locked yourself out and have to restart. It's the most-played puzzle format of the last few years for the same reason 2048 was: it fits in a minute and it's genuinely satisfying to solve.
You can pour from one tube to another only if the top colour in both matches, or the destination is empty — and only if there's room. The whole matching top layer pours at once. Win by getting every tube to a single colour.
Usually you can't — a locked rack has to be undone or restarted. The way to avoid it is to keep at least one tube empty or nearly empty for as long as possible.
Yes — tap the source then the destination. It runs in the browser with nothing to install.