Lights Out

How to play Lights Out

• Lights Out is a puzzle where you turn off every light on the board. Tapping a light flips it and the lights directly above, below, left and right of it (on becomes off, off becomes on).
• Turn all the lights off to win. Every puzzle here can be solved.
• There are five board sizes, from 3×3 to 7×7. 5×5 is the size of the original handheld game; if you are new, start with 3×3.
• “Fewest” is the smallest number of moves that solves the puzzle. The order of your taps doesn’t matter, and tapping the same light twice cancels out.
• Stuck? Tap “Hint” and the next light to press on a shortest solution is outlined in blue.
• The daily puzzle is the same for everyone: one for each board size, with a new set every day.
• On a computer, move with the arrow keys and press with Enter or Space. Ctrl+Z undoes a move. If you close the page, your puzzle is saved so you can pick up where you left off.

How to solve Lights Out

The classic method is called “chasing the lights.” It solves any 5×5 puzzle in three steps:

1. Chase down. Starting from the top row, press the light directly below each light that is on. Row by row, this pushes every lit light down into the bottom row.
2. Look up the bottom row. Find the pattern left in the bottom row in the table below, and press the matching lights in the top row (counted from the left).
3. Chase down again. Repeat step 1. This time every light goes out.

On 4×4, the first chase alone clears every puzzle in this game. On 3×3, 6×6 and 7×7 the bottom-row table is different (on 7×7 it has 127 patterns), so tap “Hint” when you get stuck. Chasing always works, but it doesn’t always find the fewest moves.

About Lights Out

Lights Out became widely known through the handheld electronic game released by Tiger Electronics in 1995. It is a classic “toggle” puzzle and a well-known topic in mathematics: on a 5×5 board, only 1 in 4 random patterns can be solved, so this game only deals patterns that can. This page is an independent puzzle with the same rules and is not affiliated with the original maker.