What is Hitori?
Hitori is a Japanese grid logic puzzle about removing repeated numbers. You shade some cells so every row and column has no duplicate unshaded number.
A finished Hitori puzzle also has two spatial rules: shaded cells cannot touch orthogonally, and all unshaded cells must remain connected as one white area. This online Hitori game gives you free puzzles with multiple grid sizes, three difficulties and uniqueness checking built into the generator.
- Shade cells to remove duplicate numbers from every row and column.
- Never place shaded cells next to each other horizontally or vertically.
- Keep every unshaded cell connected through its sides.
- Use circles to mark cells you know must stay white.
- Every generated puzzle is tested by a solver before it appears.
How to play Hitori online
Look for a repeated number in a row or column. At least one copy in that line must be shaded, because two equal numbers cannot both remain white.
Click or tap a square once to shade it. Click again to circle it as a confirmed white cell. Click a third time to clear the mark. The Check button looks for rule breaks without revealing the full answer.
- Start with rows or columns that contain the same number two or three times.
- When you shade a cell, circle its orthogonal neighbours because shaded cells cannot touch.
- If a cell must stay white, every matching number in its row or column must be shaded.
- Watch the white area so your shading does not split the puzzle into islands.
- Use Hint when you want one logical step instead of the full solution.
Hitori grid sizes and difficulty
Small Hitori boards are quick deduction puzzles, while larger boards create more repeated-number chains and more connectivity traps. You can switch between 5x5, 6x6, 7x7, 8x8 and 9x9 grids.
Easy puzzles favour clearer duplicate groups and lighter shading. Medium puzzles add more interactions between rows and columns. Hard Hitori puzzles use denser patterns, so you have to combine duplicate logic with the connected-white rule.
- 5x5 and 6x6 Hitori are friendly for learning the rules.
- 7x7 is a balanced everyday Hitori size.
- 8x8 and 9x9 give stronger strategy puzzles.
- Easy, medium and hard each generate a fresh unique puzzle.
- The puzzle is only shown after the internal solver confirms one solution.
Hitori strategy tips
The strongest Hitori strategy is to alternate between duplicate logic and adjacency logic. A shaded square forces its side-neighbours to stay white, and a white square can force matching numbers in the same row or column to be shaded.
Connectivity matters later in the solve. Before shading a tempting square, ask whether that move would isolate a white corner, split a corridor or block the only path between two parts of the board.
- Circle neighbours around every shaded cell.
- Mark a number white when all other copies in its row or column are forced shaded.
- Treat corners and edges carefully because they have fewer routes for connectivity.
- Search for chains where shading one duplicate immediately forces the next.
- Use the connected-white rule when duplicate logic alone stalls.
Why unique Hitori puzzles matter
A good Hitori puzzle should not ask you to guess between two equally valid shaded patterns. The logic should point to one final board.
This Hitori generator creates a candidate puzzle, solves it independently, and rejects it unless the solver finds exactly one solution. That uniqueness check is what makes the online game feel fair on easy puzzles and satisfying on hard puzzles.