Greater Than / Less Than Sudoku
Inequality signs between cells constrain which is larger
Greater Than / Less Than Sudoku is fully playable. Choose a difficulty and start solving.
Greater Than Sudoku (also called Futoshiki-style Sudoku) places < and > inequality signs between adjacent cells. The sign indicates which of the two cells must hold the larger value. Some variants replace all given digits with inequality signs; others provide a hybrid. The constraints create chains of reasoning: if A > B > C > D, then A ≥ 4, B ≥ 3, C ≥ 2, D ≥ 1.
Like all Sudoku variants, Greater Than / Less Than Sudoku builds on the classic 9×9 foundation. Every row, column, and 3×3 box must contain each digit from 1 to 9 exactly once. The variant constraint is added on top of these standard rules, never replacing them.
If you're new to Sudoku, start by learning the basic rules and techniques before attempting variants.
Techniques Useful for This Variant
| Technique | How it applies |
|---|---|
| Pencil Marks / Notes | Essential for tracking candidates alongside the variant constraint |
| Obvious Singles | Cells narrowed to one candidate by the combined constraints |
| Hidden Singles | Digits with only one valid cell in a unit after variant elimination |
| Pairs and Triples | Locked candidates exposed by the additional constraint |