Lights Out!
Turn every light off. Each press toggles a light and its four neighbors.
A new daily puzzle at 00:00 UTC.
Each press toggles a light and its ↑ ↓ ← → neighbors.
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All lights out!
Progress saves on this device.
Keyboard: Tab to the board, arrow keys to move, Enter or Space to press a light.
How to play Lights Out
The goal is a completely dark board. Pressing any square changes its light and its orthogonal neighbors: on becomes off, and off becomes on. Diagonals stay unchanged, and edges do not wrap around. You can press an unlit square too.
Every puzzle here can be solved. Minimum is the fewest presses needed from the starting board. The 3 × 3 board is a useful place to learn; 5 × 5 and 7 × 7 give you more room to experiment.
A few useful strategies
- Two presses cancel out. Pressing the same square twice restores the affected lights. The order of different presses does not change the final board.
- Work from the top down. Press directly below each lit square in the row above to clear that row. Keep going toward the bottom. The last row tells you whether your chosen first-row presses worked; if it remains lit, try a different first-row pattern.
- Use a hint when you get stuck. Hint marks one square from a shortest solution to your current board. Show solution marks all the squares to press once, in any order; it never plays the moves for you.
Daily puzzles, records, and saving
Each board size has its own daily puzzle, shared by everyone for that UTC date. New puzzles arrive at 00:00 UTC. You can finish an older puzzle while it stays open; reopening Daily or changing size loads the current date.
Undo, Hint, and Show solution mark an attempt as assisted. An assisted clear still solves the puzzle, but only unassisted attempts set best records. Undo takes back a press and reduces the move count. Restart begins a fresh attempt at the same board.
Your latest puzzle in each mode and size, plus your records, save in this browser. Active time starts on your first press and pauses while the tab is hidden. Free play offers new puzzles whenever you want. Progress stays on this device and is unavailable if browser storage is blocked or cleared.
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