Futoshiki Online Free
Sudoku with inequality signs. Put every number once in each row and column, and make every < and > between squares true.
Tap a square, then a number. Notes pencils in possibilities.
What is Futoshiki?
Futoshiki is a number logic puzzle: fill an n × n grid so every row and column contains the numbers 1 to n exactly once, and every inequality sign between two neighbouring squares is true. A < sign points at the smaller number, so 2 < 4 is fine but 4 < 2 is not.
Its name is the Japanese word for “inequality”. It plays like a small Sudoku without boxes, where the signs do the work that given numbers do in Sudoku. That makes it a good way to practise comparing and ordering numbers.
How to play Futoshiki
- Fill every square with a number from 1 to the size of the grid: 1 to 4 on a 4 × 4 grid, 1 to 5 on 5 × 5, and 1 to 7 on 7 × 7.
- Each number appears exactly once in every row and every column.
- Signs between squares must be true. The narrow end of < or > points at the smaller number; ∧ and ∨ do the same for squares above and below each other.
- Numbers in white are given. Repeated numbers and broken signs turn red. Tap a square, then tap a number or type it. Turn on Notes (or press N) to pencil in possibilities, and use ⌫ to clear a square. Arrow keys move between squares.
- Every puzzle is made fresh and checked to have exactly one solution, so it can always be solved by logic without guessing. Use Hint if you’re stuck, and pick a size at the top of the board.
Futoshiki skills
- Comparing numbers with < and >
- Ordering numbers
- Logical deduction
Level: Ages 8 and up
Tips for Futoshiki
A square that is smaller than another can never be the biggest number, and a square that is bigger can never be 1. Note those out first.
Follow chains of signs. On a 5 × 5 grid, if a < b < c, then a is at most 3 and c is at least 3.
When only one square in a row or column can hold a number, it must go there, even if that square still has other notes.
New to grids like this? Try the 4 × 4 Sudoku for kids first.
Futoshiki questions and answers
How do you play Futoshiki?
Fill the grid with the numbers 1 to n so each row and column contains each number once. Every inequality sign between two squares must be true: the narrow end points at the smaller number.
What does Futoshiki mean?
Futoshiki is the Japanese word for “inequality”, after the greater-than and less-than signs that make the puzzle work.
How is Futoshiki different from Sudoku?
Futoshiki has no 3 × 3 boxes, and it uses only a few given numbers. Instead, inequality signs between squares tell you which number is bigger, and you combine them with the row and column rule.
Does every Futoshiki puzzle have one solution?
Yes. Every puzzle here is made fresh and checked by a solver, so there is exactly one way to fill the grid.
Is Futoshiki good for kids?
Yes. The 4 × 4 puzzles only use the numbers 1 to 4, and every sign is a quick comparison, so children from about 7 or 8 can solve them. It’s good practice with < and >.