How to play Hitori

The goal

The rules

• No number may appear more than once, unshaded, in any row or column.
• Shaded cells never touch each other side by side (touching at a corner is fine).
• All the unshaded cells must stay joined into one area, moving up, down, left and right.

Playing

• Tap a cell to shade it, tap again to circle it (your note that it stays), and once more to clear it.
• Drag across cells to paint them all the same way: whatever a tap would have done to the first cell.
• Unmarked cells count as unshaded, so you never have to circle anything. The puzzle is solved the moment the shading follows all three rules.
• Undo takes back your last change. Hint fixes a wrong mark, or settles a cell you can work out next.
• Check outlines any wrong marks in dashed red without giving anything else away.

Spotting mistakes

• Two shaded cells that touch turn red.
• Unshaded cells cut off from the rest are tinted red.
• A repeated number turns red once both copies are circled, or once every cell in its row or column is marked.

Tips

• A number between two equal numbers (5 3 5) always stays: circle it.
• Two equal numbers side by side (4 4) means one of them stays, so every other 4 in that line is shaded.
• Every cell next to a shaded cell stays: circle them.
• If shading a cell would wall off part of the grid, that cell must stay.

Difficulty

• Easy: a 5×5 grid.
• Normal: a 7×7 grid you can solve step by step.
• Hard: a 9×9 grid where you will need to try shading a cell and see whether it breaks a rule.
• Every puzzle is new. Your best times are kept for each difficulty.

Keyboard

• Arrow keys move, Space or Enter cycles, S shades, C circles, Backspace clears, H hints, K checks, and Ctrl or ⌘+Z undoes.

Questions

Strategy guides