Sokoban — the free browser box-pushing puzzle, eight levels and a move budget

Sokoban is the warehouse-keeper puzzle: a little grid, a handful of crates, and the same number of marked squares to get them onto. The whole game rests on one asymmetry. You can push a box by walking into it, but you can never pull one back, and you can only ever shift one box at a time — so a crate you shove one square too far may be somewhere no amount of walking will ever recover. Half of playing well is deciding where to stand before you touch anything.

There are eight levels here, small enough to read at a glance on a phone and getting harder as you go. Each one carries a move budget: run out before the last box is home and the run ends, and your score is simply the number of levels you cleared, so clearing three and stalling on the fourth scores 3. Every budget is roughly two and a half times the shortest possible solution — verified by a solver, not guessed — so there is real room to explore, just not room to wander forever. Free, plays in the browser, nothing to download.

How to play

• Move with the arrow keys or WASD on a keyboard, the on-screen d-pad on a phone, or by dragging across the board — a drag keeps stepping as your finger travels.
• Walk into a box to push it. There must be an empty square behind it: you cannot push a box into a wall, and you cannot push two boxes at once.
• Get every box onto a dot to clear the level. A box that is home turns green.
• Watch the move counter. Each step you actually take spends one move; bumping into a wall is free. Hit the budget with a box still loose and the run is over.
• Undo steps the board back one move, as many times as you like — but it does not refund the move, and neither does Restart. Both hand you a rescued position, not spent moves back.
• On a keyboard, U undoes and R restarts the level.

Deadlocks: the four positions you can never recover from

Because pulling is impossible, most Sokoban losses are decided several moves before you notice them. The board looks fine, you still have moves left, and the level is already unsolvable. Learning to see these four shapes before you push is the single biggest jump in skill available, and it is why Undo exists on this page.

1. The corner. A box in a corner formed by two walls can only be pushed along a line it can no longer reach — it is frozen forever. Unless that corner square is itself a target, pushing a box into one has ended the level. This is the deadlock every beginner discovers, usually on move three.

2. The wall run. A box flat against a straight wall can only ever slide along that wall; it can never come off it, because coming off would need you to stand inside the wall. So a box on a wall segment with no target anywhere along it is just as dead as one in a corner, only less obviously. Check the whole wall, not the square you are on.

3. The frozen square. Any 2×2 block made entirely of boxes and walls is immovable — pushing any member of it would require pushing another. Two boxes side by side against a wall are the common case: neither can go forward, and neither can be reached from behind. If the square happens to sit entirely on targets it is a win, and otherwise it is a loss.

4. The blocked corridor. In a one-tile-wide passage you can never get past a box to push it the other way, so a box shoved into a corridor is committed to that direction until it comes out the far end. Level 2 here is that lesson in miniature: the only route to the target runs the long way around a wall block, and the order in which you approach the box decides whether the route exists at all.

The practical habit that follows from all four: before each push, look at the square the box will land on and ask what can still push it from there. If the answer is "nothing", you have found a corner or a wall run. And when you get it wrong anyway, Undo beats Restart — both cost you the moves you already spent, but Undo hands the position back one step before the mistake instead of making you replay the level from scratch.

More games

More puzzles that reward planning ahead: Block Puzzle, Lights Out, or the 15 Puzzle. Or browse all games.