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LOGIC • STRATEGY • FOCUS

Lights Out

Test your mind by switching off the lights. Can you reach complete darkness?

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Chain Reaction

Tap one light and it flips together with its horizontal and vertical neighbours.

Lights-Off Goal

Switch off every glowing yellow cell until the entire board is dark.

Solvable Boards

Every board is guaranteed to have a solution, whichever difficulty you choose.

Choose a Difficulty

Lights Out: Strategy and Forward Thinking

Lights Out is a cause-and-effect puzzle in which every move changes several cells. Since tapping one light also flips its neighbours, success comes from building a logical chain instead of guessing.

Skills for Everyday Thinking

Larger grids demand more working memory and spatial awareness. Following each chain reaction tests your ability to plan ahead and keep a strategy on course.

Lights Out
Switch off the lights!
Moves: 0

How It Works

A light switches off if it is on and on if it is off. The cells directly above, below, left and right flip too.

Strategy

Work from the top row downward. If the final row blocks you, use a hint; it adds a two-move penalty.

What Is Lights Out?

Lights Out is a logic puzzle in which you try to darken an entire grid. Clicking one cell flips that light and its neighbours above, below, left and right. A simple switch therefore creates a chain reaction that you must plan several moves ahead.

The electronic game became widely known in 1995, but its structure is also a neat example of binary mathematics. Clicking the same cell twice cancels its effect, and the order of your clicks does not matter. This free version offers solvable 3x3, 4x4, 5x5 and 6x6 boards.

How to Play

  • Choose a grid size. Larger grids require longer chains and more careful tracking.
  • Click a cell to flip it and its edge-sharing neighbours. Diagonal cells do not change.
  • Corner clicks affect three lights, edge clicks affect four and inner clicks affect five.
  • Switch off every light. Each generated board is guaranteed to be solvable.
  • A hint highlights one useful move but adds two moves to your score.
  • Lower move counts rank higher on the leaderboard for the selected grid size.

Solution Method: Chasing the Lights

  • Start at the top. For every lit cell in the first row, click the cell directly beneath it. This turns off the row above.
  • Continue downward. Repeat the same process row by row. You are pushing every remaining light toward the bottom.
  • Watch the final pattern. If lights remain in the last row, that pattern tells you which cells in the first row to press before chasing again.
  • Do not click randomly. An unplanned move can relight several cells you already cleared.
  • Remember the two-click rule. Pressing the same cell twice returns the board to its previous state.
  • Save hints for real dead ends. The two-move penalty can make a large difference on the leaderboard.

What Does Lights Out Train?

  • Systematic problem-solving: You replace guessing with a repeatable method.
  • Cause and effect: Every action changes several connected parts.
  • Backward planning: The final row helps you infer what must happen at the start.
  • Spatial attention: You track crosses of neighbouring cells across the grid.
  • Patience: One careless click can undo a long sequence of correct moves.

Frequently Asked Questions

Is Lights Out free to play?

Yes. You can play every grid size for free without registering or installing an app.

What is the goal?

Switch off every light on the board. Each click flips that cell and its neighbours above, below, left and right.

Does every puzzle have a solution?

Yes. The game generates boards by applying valid moves, so every starting position shown here is solvable.

What is the easiest solution method?

Use light chasing: for each light in a row, click the cell immediately below it, then continue downward one row at a time.

What if lights remain in the bottom row?

The remaining pattern identifies which cells in the top row need an initial click. Apply those clicks and chase the lights downward again.

What happens if I click one cell twice?

The second click reverses the first, so the net effect is zero. The order of clicks also does not change the final board.

Do hints have a cost?

Yes. A hint highlights a useful cell and adds two moves to your score.

Which skills does the game develop?

It trains systematic problem-solving, spatial attention, chain-reaction awareness and backward planning.

Turn Out the Lights

Choose a grid and start playing now. There is no registration and every board has a solution.

▶ Start Game

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