Hitori
Hitori is a logic puzzle on a grid filled with numbers. Shade some cells so that no number appears twice in any row or column. Shaded cells may never touch side by side, and all the unshaded cells must stay connected in one group.
How to play
Every Hitori here has exactly one solution and can be solved by logic alone. The grid grows from 5×5 at Easy to 9×9 at Expert, and the level is set by the hardest technique the puzzle needs.
- No number repeats among the unshaded cells of a row or column.
- Shaded cells never touch side by side (diagonally is fine).
- All unshaded cells form one connected group.
Playing on this site
- Tap a cell to shade it, tap again to circle it as kept, and once more to clear it.
- Drag across cells to paint the same mark along the way; the whole drag is one undo step.
- With a keyboard, use the arrow keys to move and Space to cycle the mark.
- Circles are only a helper: the puzzle is solved as soon as the shading is right.
- Hint points out wrong cells first, then names the next technique and highlights where it applies.
- Your puzzle is saved in this browser, so you can come back to it later.
Techniques by level
Every technique the solver knows, from easiest to hardest. A puzzle's level is the hardest one it needs.
Easy
- Beside a shaded cell
- Shaded cells never touch side by side, so the cells around this one stay unshaded.
- Same number, same line
- This number stays unshaded, so the same number elsewhere in its row or column is shaded.
- Nothing to repeat
- No other cell can keep this number in its row or column, so it never needs shading.
- Between twins
- One of the two equal numbers on either side is shaded, so the cell between them is not.
- Twin pair
- Of two equal numbers side by side, exactly one stays. Every other copy in that line is shaded.
Medium
- Keep it connected
- Shading this cell would cut the unshaded cells in two, so it stays unshaded.
Hard
- Look one step ahead
- The other choice here breaks a rule after a few simple steps.
Expert
- Contradiction
- Assume the opposite in the marked cell and a rule breaks a few steps later. So it can only be this.
Questions
What is the best first move in Hitori?
Look for three equal numbers in a line, or two equal numbers with one cell between them: the middle one stays, and the cells beside any shaded cell stay too.
Will I ever have to guess?
No. Every puzzle has exactly one solution that logic alone reaches, at every level.
Is Hitori free to play here?
Yes. Every level is free, with no account and no sign-in.