What is Futoshiki?
Futoshiki (Japanese for "not equal") is a logic puzzle played on a square grid. Your goal is to fill every cell with a number so that no number repeats in any row or column — just like a Latin square. Inequality signs (< and >) placed between some neighboring cells add an extra layer: the sign must always point from the smaller number toward the larger one.
How to play:
- Choose a grid size and how many puzzles you want to solve, then click Start Puzzle
- Tap or click a cell to select it, then tap a number button below the grid
- On desktop, you can also type numbers directly and move between cells with arrow keys
- Press Backspace, Delete, or the ✕ button to clear a cell
- Blue cells are given clues and cannot be changed
- The puzzle completes automatically the moment the grid is filled correctly
Reading the signs:
- < between two cells: the left cell is smaller than the right cell
- > between two cells: the left cell is larger than the right cell
- ∧ between two stacked cells: the top cell is smaller than the bottom cell
- ∨ between two stacked cells: the top cell is larger than the bottom cell
- A simple memory aid: the open (wide) end of every sign faces the larger number
Solving tips:
- Look for chains of inequalities (like a < b < c) — these force extreme values. On a 4×4 grid, a chain of three cells means the smallest must be 1 or 2
- The largest number can never sit on the small side of a sign, and 1 can never sit on the large side
- When a row is missing only two numbers, check whether a sign between them decides the order instantly
- Every puzzle here is generated with exactly one solution
Scoring:
- Total Time: How long the full session took
- Avg per Puzzle: Total time divided by puzzles solved
- Hints Used: Each hint fills one correct cell — fewer is better