Matchstick Math
Move one matchstick to fix the equation.
Play now →Lights Out
Click a light and it flips — along with its four neighbours. Turn the whole board off in as few moves as you can. Every puzzle here is guaranteed solvable; how close to optimal can you get?
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Lights on
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Best moves
Click a light to flip it and its neighbours. Turn everything off!
How to play
- Study the board — some lights are on.
- Click any light to flip it and its up/down/left/right neighbours.
- Turn every light off to win the board.
- Your score is the number of moves — fewer is better. "New game" deals a fresh puzzle.
Frequently asked questions
What is Lights Out?
Lights Out is a classic grid puzzle: clicking any cell flips that light and its four neighbours. The goal is to switch every light off. It looks simple, but the flips interact in surprising ways.
Is every puzzle solvable?
Yes — here every board is generated by pressing a random sequence from the all-off state and then scrambling, so a solution always exists. You can always win by replaying those presses, though finding them is the game.
What is a good number of moves?
The generated boards usually have an optimal solution of 5–10 moves. Solving within about 12 is strong play; finishing in single digits means you found a near-optimal path.
Is there a strategy?
The classic technique is "chasing the lights": light chasing — click cells in the second row to fix the first, then the third row to fix the second, and so on. The bottom row you end up with determines which first-row presses you needed.
Does clicking the same cell twice help?
Two presses cancel out but still count as two moves, so it is never efficient. If you feel the urge to double-click, some earlier press was the one you actually wanted.