Nut Sort Puzzle is a free online nuts-and-bolts color sorting game you can play in the browser with no download and no account. Tap a bolt to lift the matching nuts off the top of its thread, tap another to spin them back on, and keep going until every color is gathered on a bolt of its own. Two things separate it from the tube-and-ball sorters: the bolts are not all the same size, so a short four-thread bolt is really only useful as a finished home while a tall seven-thread one is the staging space you plan around, and from level seven only the top nut of each bolt is showing — the rest read as a grey question mark until you unscrew far enough to uncover them. Fifteen levels run from three colors on five even bolts to eight colors, five nuts deep, with most of the board hidden. Every board is dealt by unwinding a solved one, so a way through always exists, and unlimited undo plus one spare bolt per level are there for when you thread yourself into a corner.
How to play Nut Sort Puzzle
- Every bolt holds a stack of colored hex nuts. The goal is to end with each color gathered on a single bolt.
- Tap a bolt to unscrew the nuts on top of it. All the matching nuts in that run lift together, and they float just above the thread so you can see what you are carrying.
- Tap a second bolt to thread them on. A bolt accepts them only if its own top nut is the same color, or if it is completely empty. Tap the first bolt again to put them back.
- Bolts are different heights. Some take only four nuts, others up to seven, and the number a bolt can still take is as much a part of the puzzle as the colors on it.
- From level seven the boards are hidden: only the top nut of each bolt is showing and everything under it is a grey question mark. Unscrew the nut above and the next one is revealed for good.
- A bolt lights up when it holds a whole color group, which is how you know that color is finished.
- Undo steps back one move at a time, as far as you like. Extra Bolt adds one more empty bolt for the rest of the level — one per level, and it is the way out of a board with no moves left.
- A solve with no undo and no spare bolt is three stars. The spare bolt costs more than an undo does.
- New Board deals a different arrangement of the same level. Replaying a level you have already seen brings back the same board until you ask for a new one.
Tips
- Empty bolts are the whole game. They are the only place a color that is buried can go, so spending one to park a single nut is usually the move that costs you the level.
- Read the heights before the colors. A four-thread bolt can never be a staging area — anything you put there you are close to committing to — while a tall bolt is where you unpick a tangle.
- Look for the color that is nearly home. Joining two halves of one color frees the space that everything else needs, and it is almost always cheaper than it looks.
- On hidden boards, unscrew where you learn the most. A tap that uncovers a nut on a bolt you know nothing about is worth more than a tidy-looking move that reveals nothing.
- A hidden nut is only hidden once. There is no memory test here — anything you have uncovered stays face up even if you bury it again, so exploring early is free information.
- Do not fill a bolt to the top with a color that has nuts elsewhere. A full bolt accepts nothing, and a full bolt of the wrong count is a dead end you have to unpick.
- When you run out of moves, undo before reaching for the spare bolt. The jam is usually two or three moves old, and undoing costs you far less than the bolt does.
- Count what a color still needs. If four of a color are already stacked and the level puts four to a bolt, that bolt is done — stop feeding it and stop planning around it.
FAQ
Is Nut Sort Puzzle free to play?
Yes. It runs in your browser with no download, no sign-up and nothing to buy. All fifteen levels are included and unlock in order as you clear them.
Is every board solvable?
Yes, by construction rather than by luck. Each board is built by taking a finished one and running the player's own moves backwards, so the path back to solved is one the rules allow. It is not always an easy path, but it is always there.
What are the grey nuts with a question mark?
Hidden nuts, which start appearing at level seven. On those boards only the top nut of each bolt is visible and everything beneath is unknown until you unscrew down to it. Once a nut has been revealed it stays revealed, so it is a puzzle about exploring safely, not about memorising.
Why are the bolts different heights?
Because it is the main thing that makes a nut board play differently from a rack of test tubes. When every container is the same size, capacity is something you can ignore. Here a short bolt fills up fast and a tall one is the only place to unpick a mess, so which bolt you use matters as much as which color you move.
What happens if I get stuck with no moves left?
The game says so above the board rather than leaving you tapping at it. Undo as far back as you need, or spend the level's one spare bolt to open up a free space. Neither ends the level — there is no way to actually lose.
How is this different from Ball Sort or Water Sort?
The core rule is the same family — move onto a matching color or an empty container. What changes here is that the containers vary in size and part of the board is concealed, so you are planning around capacity and around what you do not yet know, rather than solving a fully visible board of identical tubes.
Is there a time limit?
No. There is no clock, no move limit and no way to fail a level. Undo is unlimited; using it only costs stars.
Does Nut Sort Puzzle work on a phone?
Yes. The bolts reflow into rows that fit the screen and stay finger-sized, and the game plays in portrait, so there is no need to rotate the device.