Liquid sort games: how they work, and free ones
Liquid sort games give you a rack of test tubes filled with layers of coloured liquid, all jumbled up, and ask you to pour them until each tube holds one colour. They’re quiet, they go on forever, and they’re much harder than they look after about level thirty.
The pour rules
Every liquid sort game works the same way.
- You pour from the top of one tube into another.
- The tube you’re pouring into must have the same colour on top, or be empty.
- All of the matching colour pours at once, or as much as fits.
- A tube is done when it holds one colour and nothing else.
There’s no timer in almost any of them, no punishment for a wrong pour, and usually unlimited undo. All of the difficulty is in the planning.
What actually makes a level hard
Not the number of colours. The amount of empty space. Two boards with eight colours each can be easy or brutal depending on whether you have two spare tubes or none.
That’s the thing to remember: your empty tubes are the only thing you’ve really got, and every pour either spends some or wins some back. Three habits follow from it.
Don’t fill your last empty tube unless something can come back out. This one rule prevents most stuck boards.
Bring a colour together whenever you can. A colour spread across three tubes is three separate problems. Merging them looks like a wasted turn and is usually the best move on the board.
Read the buried layers. The colour at the bottom of a full tube controls the order of everything above it. Plan upwards from the worst-buried colour rather than downwards from the tidiest tube.
Can a liquid sort level be impossible?
Yes, and this is the honest answer to a question a lot of players quietly wonder about.
Many liquid sort games shuffle their levels at random and never check them. A random pour of colours into tubes isn’t automatically solvable, so impossible levels genuinely go out. Developers skip the check because it’s expensive: working out whether one of these puzzles has an answer is NP-complete, proven in 2022 for both the liquid and ball versions.
If you’ve been stuck a long time, our free water sort solver will settle it. It works on any normal liquid sort board, gives you the shortest set of pours, and says so plainly when there’s no answer at all. It runs entirely in your browser and nothing is uploaded.
A liquid sort game where the bottles disagree
Here’s the odd thing about this whole genre. Every game in it, from test tubes to bolts to hoops, uses exactly one kind of container — something you can only touch from the top. Change the pictures all you like and the puzzle underneath never moves.
Glasswort changes the container instead of the paint. It’s set on an apothecary’s bench, and there are three kinds of glass.
- Phials — the classic tall tube. Pour from the top, exactly as you’d expect.
- Retorts — a round bottle with a spout at its foot. It fills at the top and empties from the bottom, so the first colour you pour in is the first one back out.
- Basins — a shallow open dish. It takes any colour while it has room and you can lift either one, but it’s too shallow to ever finish a colour, so it has to be left empty at the end.
That turns your instincts upside down. A colour stuck at the bottom of a phial is your biggest problem. The same colour at the bottom of a retort is already in your hand.
There are 120 levels across five chapters, and each chapter introduces one bottle before mixing them together. The game solved every board before it shipped, so no level can be impossible, and the target beside each one is a real minimum rather than a guess. After 120 there’s an endless shelf, plus one puzzle a day that’s the same for everybody.
Every colour also carries its own small mark, so the puzzle never depends on telling two shades apart.
It’s free, there’s no download and no account, and it works on a phone.
Questions
Are liquid sort and water sort the same thing? Yes. Different names for one puzzle, along with colour sort, bottle sort and test tube games.
Do these games have an end? Most mobile ones don’t — they keep making new levels forever. Glasswort’s 120 stop on purpose, so that finishing it means something.
Is it free? Glasswort is completely free, with nothing to buy or unlock.