Greater Than / Less Than

Inequality signs between cells constrain which is larger

What is Greater Than / Less Than?

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.

At a Glance

Constraint typeCell Relationships
Typical givens18–24
Difficulty rating ★★★☆☆ 3/5
Avg. solve time — Easy7 min
Avg. solve time — Medium16 min
Avg. solve time — Hard32 min
Avg. solve time — Expert58 min

How to Solve Greater Than / Less Than

TechniqueWhat it doesLevel
Chain Inequality — Minimums Link inequalities in a chain: if A > B > C, then A ≥ 3, B ≥ 2, C ≥ 1. Use these minimums to prune candidates immediately. Beginner
Chain Inequality — Maximums In the chain A > B > C > D, also bound from above: A ≤ 9, B ≤ 8, C ≤ 7, D ≤ 6. Beginner
Inequality Propagation After placing a digit, check all inequality arrows from that cell and eliminate impossible values from its neighbours. Intermediate
Forced Single via Range When an inequality chain reduces a cell's valid range to a single digit, place it directly. Intermediate

Average Solve Times

Easy
7 min
Medium
16 min
Hard
32 min
Expert
58 min

Frequently Asked Questions

Are given digits provided?
Our puzzles include some given digits alongside the inequality signs.
Can inequality signs replace all givens?
Some harder puzzles use only inequalities with no given digits — the ratio depends on difficulty.