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.
Where to play it
If it was Sudoku you came for, the level is the choice that matters more than the variant - Hitori and Sudoku part ways on the rules, but a Sudoku grid can be a two-minute warm-up or an hour of work depending on nothing but how much of it you are given.
Difficulty and type are two separate dials here: the type sets the extra rule, the level sets how much of the grid you start with. Easy Sudoku leaves 36 of the 81 cells filled, so there is always an obvious next move somewhere; Evil Sudoku leaves 23, with no easy moves at all. Take it at the gentler end while the pattern is still new, and move up once it stops being a fight.