Sudoku and Futoshiki are both grid-based logic puzzles you solve by pure deduction, so solvers naturally wonder how alike they really are. The short answer: Futoshiki is close 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: Usually 5×5 (4×4–9×9)
- Closeness to Sudoku: Close
- Also called: Unequal, Hutosiki, More or Less
What is Futoshiki?
A small Latin-square grid where inequality signs between cells tell you which neighbour is larger. Here are the rules in full:
- Fill an n×n grid so each row and column holds the numbers 1–n exactly once.
- Between some cells sit < or > signs — the numbers must obey them.
- A few numbers may be given to start; the rest come from the inequalities alone.
See a Futoshiki grid
Futoshiki is a small Latin square — each row and column holds 1 to n once — steered by inequality signs. Here is a solved 3×3 example: every row and column has 1, 2, 3, and the signs 2 < 3 and 3 > 1 are obeyed.
A solved 3×3 Futoshiki: Latin-square rows and columns, plus the inequality signs.
The row-and-column rule is Sudoku's own, minus the boxes, and the signs work exactly like Greater Than Sudoku. So a Sudoku solver already has every tool Futoshiki needs — it is Sudoku with the boxes swapped for order clues.
What Futoshiki shares with Sudoku
- The row-and-column "each number once" rule is exactly Sudoku's, minus the boxes.
- The inequality signs work just like Greater Than Sudoku.
- Both are solved by naked and hidden singles once constraints are combined.
How Futoshiki differs from Sudoku
- There are no 3×3 boxes — only rows and columns constrain each number.
- Grids are small (often 5×5), so the whole puzzle turns on the inequality chains.
- Numbers go 1–n for the grid size, not always 1–9.
Do Sudoku skills transfer?
Futoshiki is a gentle way to drill the bread-and-butter of Sudoku: naked and hidden singles, plus the same inequality reasoning that powers Greater Than Sudoku. It is Sudoku with the boxes swapped for order clues.
Brush up on the technique that carries over: Naked Single.
The verdict
Futoshiki is essentially boxless Sudoku steered by inequalities — the same core logic on a smaller board.
Prefer to stay with Sudoku?
If Futoshiki appeals, these Sudoku variants scratch the same itch and you can read up on each here: