Every tap flips a light and its four neighbors. Turn the whole grid off in as few moves as you can. Stuck? The solver shows exactly which lights to press.
Runs entirely in your browser. Nothing is uploaded to any server.
Puzzles are made by pressing random lights on a dark board, so a solution always exists.
The solver calculates the fewest presses needed, so you can aim for a perfect solve.
Show one move or the full solution to see how the maths behind the puzzle works.
Lights Out was released as a handheld game by Tiger Electronics in 1995. Because pressing a light twice undoes it, and the order of presses does not matter, each light is either pressed once or not at all. That turns the puzzle into a system of linear equations modulo 2, one equation per light, which the solver on this page solves with Gaussian elimination.
On the classic 5x5 board, not every pattern is solvable and every solvable pattern has four different solutions. The solver tries them all and shows the shortest. A popular manual method is light chasing: press the light below every lit cell, row by row, then use a known pattern for the last row.
Any sequence of the same presses gives the same result.
Two presses of one light cancel, so never press a light more than once.
Clear row by row by pressing beneath each lit light.
Yes. Each puzzle is created from a dark board with random presses, so it can always be undone.
It is the minimum number of presses that solves this exact puzzle, calculated by the built-in solver.
Yes. Undo restores the board but adds one to the move counter, like pressing the same light again.
Work from the top row down, pressing the light directly below each lit light. Only the bottom row will remain, which you solve with a top-row pattern and repeat.
Your best moves compared with the minimum are saved for each grid size in this browser.
More free tools from My Panda Toolbox.