What is Akari?
Akari, also known as Light Up, is a logic puzzle about placing light bulbs on a grid of white and black cells. Bulbs shine along their row and column, and the goal is simple: light up every white square without any two bulbs lighting each other.
Numbered black cells give the clues. Play Akari online free here, from gentle 7×7 grids to wide 14×14 boards.
Where Akari comes from
Akari, also called Light Up, was made popular by Nikoli, the Japanese publisher behind many of the world’s best-known logic puzzles, including sudoku. Akari means “light” in Japanese, and the goal is to light every white cell with bulbs that shine along their row and column until they hit a black wall.
How to play here
With a mouse, left-click a white cell to place a bulb and right-click to mark a cell that cannot hold one. On a phone, tap to place a bulb and switch on Mark mode (the flag button next to Undo) to place marks instead. Lit cells are shaded, so you can see at a glance what is still dark.
A step-by-step way to solve
- Start with the black cells numbered 4 and 0. A 4 needs a bulb on all four sides. A 0 means none of its neighbors can hold a bulb, so mark them all.
- Use numbers against the edge. A 3 against the border, or a 2 in a corner, has exactly as many free sides as bulbs it needs, so every free side gets a bulb.
- Look for dark cells only one spot can light. If a white cell can only be reached from one position, that position must hold a bulb.
- Mark as you go. Every bulb rules out every other cell in its lines. Marks make the next deduction easy to see.
- Check the numbered walls last. A wall that already has its bulbs forces marks on its remaining neighbors.
Why play Akari?
Akari is one of the friendliest logic puzzles for beginners: the rules are short, the board fills up fast, and every step is a clear deduction. Larger grids stay interesting because lights and walls interact across the whole board. If you enjoy it, try Tents or Hitori, which use a similar mix of marking and placing.
How to play Akari
- Place light bulbs in white cells. Each bulb lights its whole row and column until a black cell blocks it.
- Every white cell must be lit by at least one bulb.
- No bulb may shine on another bulb.
- A number on a black cell says exactly how many bulbs touch it, above, below, left and right.
Akari tips
Start with 4s and 0s
A black cell with 4 needs bulbs on all four sides. A 0 means none of its neighbors hold a bulb, so mark them all as empty.
Find cells only one bulb can reach
If an unlit white cell can only be lit from one position, the bulb must go there.
Mark cells that cannot hold a bulb
Put a dot on every cell that is already lit or is ruled out by a number. Dots keep the board readable on large grids.
Frequently asked questions
Is Akari the same as Light Up?
Yes. Akari is the Japanese name, meaning light, and the puzzle is sold in English as Light Up. The rules are identical.
Can a bulb light cells behind a black cell?
No. Light travels in straight lines and stops at the first black cell or the edge of the grid.
Who invented Akari?
Akari was first published by Nikoli, the Japanese puzzle publisher that also made sudoku famous.
