Sudoku and Hitori are both grid-based logic puzzles you solve by pure deduction, so solvers naturally wonder how alike they really are. The short answer: Hitori is moderate to Sudoku. Below we lay out what the two share, where they part ways, and whether the skills you have built on Sudoku will carry over.
- Grid: Square number grid
- Closeness to Sudoku: Moderate
What is Hitori?
A grid of numbers where you shade cells so that no number repeats in any row or column among the cells left unshaded. Here are the rules in full:
- Shade cells so that no number appears twice unshaded in any row or column.
- Shaded cells may never touch each other orthogonally.
- All the unshaded cells must stay connected in one group.
See a Hitori grid
In Hitori you shade cells so that no number repeats among the unshaded cells of any row or column. Below, a row held two 3s; shading one (dark) removes the duplicate, leaving the visible numbers all different.
A Hitori grid: shade cells (dark) so no number repeats among the unshaded cells of any row or column — shaded cells never touch, and the rest stays connected.
The core goal — no repeated number in a row or column — is lifted straight from Sudoku. But Hitori works in reverse: instead of placing digits, you remove duplicates by shading, then keep the shaded cells apart and the unshaded ones connected. The instinct Sudoku builds — "this row already has a 3" — is exactly what Hitori runs backwards.
What Hitori shares with Sudoku
- The core goal — no repeated number in a row or column — is lifted straight from Sudoku.
- Both are solved purely by logic, marking what must stay and what must go.
How Hitori differs from Sudoku
- In Hitori you remove duplicates by shading, rather than filling empty cells.
- The connectivity and no-touching rules for shaded cells have no Sudoku equivalent.
- There are no boxes and numbers may legitimately repeat once shaded.
Do Sudoku skills transfer?
No technique transfers cell-for-cell, but the instinct Sudoku builds — "this row already has a 5, so the other 5 can't stay" — is exactly the reasoning Hitori runs in reverse.
The verdict
Hitori inverts Sudoku's no-duplicates rule: instead of placing digits, you shade the extras away.