Lights Out

How to play

Every light starts off, then the game scrambles the board by pressing a set number of random cells — that count is shown as Par, and it depends on the difficulty you pick (4, 7, or 12 presses). Press any cell to toggle it and its up-to-four orthogonal neighbors; corner and edge cells have fewer neighbors, so they flip fewer lights. Order never matters, and pressing the same cell twice just cancels itself out, so the shortest solution never repeats a cell. Turn every light off to finish — the status line then tells you whether you beat par, matched it, or came in over it. Switching the difficulty dropdown immediately scrambles a fresh board at that depth, and there's no undo, so if you lose track of what you've pressed, New puzzle is the fastest way back to a clean slate.

Frequently asked questions

Is my progress saved?

No — nothing about this game is saved anywhere. There's no local storage, no account, and no history of past puzzles; your move count, par, and board state exist only in the page's memory for as long as you keep it open. Refresh the page, close the tab, or click New puzzle, and everything resets to a brand-new scrambled board with no record of what came before. If you want to compare attempts over time, you'll need to jot your move counts down yourself.

Is there a strategy?

Yes — the standard technique is called “light chasing.” Work through the board row by row from the top: whenever a light in the current row is still on, press the cell directly below it in the next row. That pushes every unwanted light down toward the bottom row one at a time. Once only the bottom row has lights left on, a small set of known fixed patterns, based on how the original top row looked, tells you exactly which top-row cells to press to clear the rest in one final pass.

Can I beat par?

Sometimes. Par simply reflects how many random presses the generator used to scramble the board, not the shortest possible solution — a 7-press scramble can occasionally be undone in fewer moves if some of those presses overlapped in a way a smarter route avoids. There's no guarantee a shorter solution exists, though, so matching par is already a solid result, and beating it by even a move or two on Hard is a good sign you're spotting cleverer routes rather than just getting lucky.