What Is Hitori?
Hard Hitori is designed for players who already understand the basic rules and want more interaction between number logic and spatial logic.
The 7x7 grid creates longer scans and more situations where the obvious duplicate is not the safe black cell.
A strong solve in Hard Hitori often depends on preserving routes through the white cells while still removing every repeated visible number.
How to Play Hitori
Hard Hitori is less about quick duplicate removal and more about proving which cells must stay white.
- 1Identify duplicate groups that overlap with several other duplicate groups.
- 2Use black-cell adjacency to force nearby duplicates white.
- 3Check whether a candidate black cell would split the white area into separate regions.
- 4Delay uncertain cells and solve the surrounding constraints first.
- 5Use undo or hints only after checking both number uniqueness and connectivity.
Hard Hitori Strategy
- •7x7 creates a noticeably deeper Hitori solve than Easy or Medium.
- •Hard mode emphasizes connectivity traps and multi-row duplicate chains.
- •This page is best for players who want a deliberate logic puzzle rather than a quick warm-up.
Hitori FAQ
What makes Hard Hitori difficult?
Hard Hitori uses a 7x7 board with more duplicate crossings and more ways to accidentally cut off the white cells.
Should I guess in Hard Hitori?
Try not to. Most hard boards can be reduced by checking adjacency, forced white cells, and whether the white area stays connected.
What is different about 7x7 Hitori Hard?
7x7 Hitori Hard changes the grid size and the density of forced black cells, so the solve has a different balance of duplicate cleanup and connectivity logic.
Are all repeated numbers in Hitori black?
No. Repeated numbers tell you at least one copy may need to be shaded, but the adjacency and connectivity rules decide which copy is correct.
Can black cells touch diagonally?
Yes. Black cells cannot touch above, below, left, or right. Diagonal contact is allowed.
What does the white circle mark mean?
A white circle means you have confirmed the cell should remain visible. It is a note for your solve and counts as a final white decision.