Futoshiki Solver, Step by Step
Type the given numbers into their squares. Tap the gap between two squares to set a sign; tap again to turn it round, a third time to clear it.
How to use the futoshiki solver
Choose the size, type the numbers your puzzle starts with, and tap the gap between two squares to put in a sign: once for < (or ∧ between rows, meaning the upper square is smaller), twice for > (or ∨), three times to clear it. Press Explain the next step: the solver fills in the next certain number or crosses off impossible ones, highlights the squares involved, and says why. Show the answer fills the grid at once and checks the solution is the only one.
How to solve futoshiki, step by step
Read the signs at the ends. In a 6 by 6, a square that is smaller than its neighbour can never be 6, and one that is bigger can never be 1. A chain of signs, a < b < c, pushes harder: a is at most 4 and c at least 3. Then let the signs and the rows work together. When a neighbour's largest possible number drops, the square below it in the sign drops too, and every number settled in a row comes out of the rest of that row and column. Look for the only place. A row that still needs a 6, with only one square left that can take one, has its 6. Those few moves solve every daily puzzle on this site from start to finish.
How it was checked
The solver was run on all 120 puzzles of the daily futoshiki. It found each one's stored answer and found it to be the only one; every step it explained was checked against those answers, and it never placed a wrong number or crossed off a right one. All 120 were explained from the first square to the last, without a guess.
More number puzzles
A new futoshiki is waiting every day on the daily futoshiki page. The KenKen solver and the sudoku solver explain their moves the same way. For a puzzle you hold in your hands, see our brain teasers. There are more solvers on the puzzle tools page.
Frequently Asked Questions
How do you solve futoshiki?
Start with the signs: a square smaller than its neighbour can never be the largest number, and one bigger can never be 1; chains of signs push further. Then use the rows and columns, where each number appears once, and look for a number with only one place left in a row.
What are the rules of futoshiki?
Fill the grid so every row and column holds each number once, and every inequality sign between two squares is true. Some numbers are given to start.
What does futoshiki mean?
It is Japanese for 'inequality', from the signs between the squares that make the puzzle.
Does every futoshiki have one solution?
A well-made one does, and the solver checks: if the numbers and signs you entered allow more than one, it says so.
How do I enter the signs?
Tap the gap between two squares: once for less than, twice for greater than, three times to clear it. Between rows the sign shows as an arrowhead pointing at the smaller square.