💡 Lights Out

How to play

The board is a grid of lights, some lit and some dark, and it is solved when every light is off. Clicking a light flips it and the four lights directly above, below, left and right of it, so each click changes up to five cells. Edge and corner clicks flip fewer, because the missing neighbours do not exist.

• Grid cells — click or tap a light to toggle it with its orthogonal neighbours. Diagonals are unaffected.
• 5x5, 6x6, 7x7 buttons — change the board size and immediately build a new puzzle at that size.
• Shuffle button — generates a new puzzle at the current size and resets the move counter.

Scoring

The only number is Moves, and lower is better. Every click counts, including one that undoes an earlier click. When the last light goes out the message confirms the solve, and if the count beat your previous record for that size, Best is updated. Best is kept separately for 5x5, 6x6 and 7x7, shows a dash until you have solved that size, and is lost when you reload.

Tips

• Order does not matter, only which cells you press and how often. Pressing the same cell twice cancels out and wastes two moves.
• Use the chase technique: work down row by row, and whenever a light in the row above is still on, press the cell directly below it.
• Puzzles are made by scrambling a solved board with a handful of random presses, so a short solution always exists.
• If the bottom row will not clear, the fix is a specific set of presses in the top row. Restart from the top rather than clicking at random.

Frequently asked questions