Light Up Puzzle Online

Light Up is one of the classic one-player logic games in Simon Tatham's Portable Puzzle Collection. Place bulbs to light up all the squares.

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Preparing the game board and controls.

Game Objective

Place bulbs so every blank square is lit. A bulb lights its own square and all blank squares in the same row and column until a black wall square blocks the light. Two bulbs are not allowed to shine directly on each other.

Place bulbs to light up all the squares.

How to Play

Click a blank square to place or remove a bulb.
Right-click a blank square to mark a dot, meaning you think a bulb cannot go there.
A numbered black square counts only the bulbs directly above, below, left, and right of it.
These puzzles reward careful deduction more than speed. Start with the most constrained clues, eliminate impossible choices step by step, and avoid guessing unless the puzzle specifically calls for it.

Beginner Tips

Start with numbered black squares. A 0 means all adjacent blank squares cannot contain bulbs.
One bulb can light a whole open row or column segment, so do not place bulbs in every unlit square.
If two possible bulbs can see each other along an open row or column, at most one of them can be used.