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.

Loading puzzle...

Preparing the game board and controls.

What This Game Is

Light Up is a self-contained logic puzzle built around one clear objective. Each new board gives you a fresh problem to solve, so it works well for quick sessions and repeated play.

Place bulbs to light up all the squares.

How to Play

Left-clicking in a non-black square will toggle the presence of a light in that square. Right-clicking in a non-black square toggles a mark there to aid solving; it can be used to highlight squares that cannot be lit, for example. You may not place a light in a marked square, nor place a mark in a lit square.

Most puzzles in this collection reward deduction more than speed. Focus on the most limited choices first, use the clues to narrow the board, and avoid guesses unless the puzzle mode clearly expects them.

Beginner Tips

  • Start with the area that has the strongest clue or the fewest legal options.
  • Use marks, notes, or temporary indicators if the puzzle supports them.
  • Try to preserve flexibility instead of committing too early when multiple moves look possible.
  • If the board gets messy, restart a fresh puzzle and apply what you learned from the first run.

Official Reference

If you want the full original rule explanation, examples, and advanced options, the official manual is the best reference.

Read the official manual

Frequently Asked Questions