Hitori
Left to shade: 0
- Category
- Puzzle
- Players
- 1
- Controls
- Tap
- Grid
- 6 x 6
- Loads
- No install
Controls
| Tap a cell | Shade or unshade it. |
Next up
| Tap a cell | Shade or unshade it. |
Hitori asks you to shade cells until no number appears twice in any row or column. Two further rules make it a real puzzle: no two shaded cells may touch side by side, and every unshaded cell must remain connected to the rest.
Those two constraints pull against each other constantly. Shading an obvious duplicate can isolate a corner of the grid or force two shaded cells together, so the answer is rarely the first thing you see. It is one of the most elegant of the Japanese logic puzzles for exactly that reason.
Look for a number appearing three times in a line. At most one can stay, and since shaded cells cannot touch, the arrangement is often forced immediately.
Watch for sandwiched pairs. When two identical numbers sit either side of a third cell, that middle cell can never be shaded, because shading both neighbours is illegal.
Check connectivity before committing. A shading that isolates a single cell in a corner is wrong even when it fixes a duplicate, and this is the rule most people forget.
Mark cells you know must stay. Working out which cells definitely survive is as useful as working out which to shade, and it constrains everything around them.
No number may repeat in a row or column once shading is complete, no two shaded cells may touch orthogonally, and the unshaded cells must all stay connected.
Yes, only side-by-side contact is forbidden.
You must be able to travel between any two unshaded cells moving up, down, left or right through unshaded cells.
Yes. Each is built by choosing a valid shading first and then writing the duplicates in.
No sign-up, no email, no account. Open the page and Hitori is ready to play straight away, on a phone or a desktop.