Play Futoshiki (Unequal) online Works — plays right here, unlimited puzzles
Guide updated October 2026 · Runs via WebAssembly (native port)
Futoshiki is a Latin-square puzzle with inequality signs: every row and column contains each number once, and the < and > marks between neighbouring squares must hold true. This version also has an Adjacent mode, where bars mark numbers that differ by one. The puzzle is ready below; click a square and type a digit to begin.
Controls — what does what
| Action | Keyboard | Mouse / touch |
|---|---|---|
| Select a square | Arrow keys | Left-click |
| Enter a digit | Type the digit | Click, then type |
| Pencil marks | Enter toggles pencil mode, then type | Right-click, then type |
| Clear a square | Space or 0 | Click, then Space |
| Fill all pencil marks / fill and prune obvious ones | M / H | — |
| Grey out a clue you have used | Ctrl or Shift + arrow | Left-click the clue |
| Undo / redo | U / R (or Ctrl+Z / Ctrl+R) | Game menu buttons |
FREE This is the complete game, free. Open source under the MIT licence: the complete puzzle, with a new grid every time.
Unequal is from Simon Tatham's Portable Puzzle Collection, © Simon Tatham and contributors, used under the MIT licence. Built from source by scripts/build-puzzles.mjs.
How to play
On an N×N grid, fill each square with a digit from 1 to N so that:
- each digit appears once in every row and once in every column;
- every inequality sign between two squares is true (the point faces the smaller number).
In Adjacent mode the signs are replaced by bars: a bar between two squares means their numbers differ by exactly one, and every such pair is marked, so no bar means they do not.
Sizes and difficulty
Presets run from 4×4 to 7×7 at Easy, Tricky and Extreme, and include Adjacent-mode puzzles at 5×5, 6×6 and 7×7. Custom adds Trivial (a plain Latin square with no signs) and Recursive, which needs backtracking but still has a single answer.
Solving tips
Chains of signs are powerful: in a run of three increasing squares the first cannot be N or N−1 and the last cannot be 1 or 2. A square larger than a neighbour can never be 1, and a smaller one can never be N. Combine that with the once-per-line rule and track candidates with pencil marks; press H to fill them in with the obvious eliminations already made.
Where this puzzle comes from
Unequal is part of Simon Tatham's Portable Puzzle Collection, a set of about forty logic puzzles written by Simon Tatham and contributors and released under the MIT licence. Every grid is generated on the spot, so the supply never runs out, and for the grid-logic puzzles the generator makes sure each has exactly one solution, reachable by reasoning rather than guessing. The version here is the collection's own code compiled to WebAssembly; the Game menu can save a puzzle to a file and load it again, and the Type menu changes the size and difficulty.
Frequently asked questions
Does every puzzle have a unique answer?
Yes. Even the Recursive level, which needs trial and error, is generated to have exactly one solution.
Are all inequality signs shown?
Not always. In Unequal mode some signs are left out, especially at harder levels; you are given just enough to reach one answer.
Is Futoshiki free to play here?
Yes, with no limit on the number of puzzles. Unequal is open-source software under the MIT licence, and every grid is generated fresh when you press New game.
Does it work on a phone or tablet?
Yes. A tap works as a click and the puzzle resizes to fit the screen. Puzzles whose controls use the right mouse button are easier with a mouse.
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Want a game like this on your own site?
Futoshiki (Unequal) isn't ours to give away — we host it, we didn't write it. But eleven of the games here we did write from scratch, and those are free for anyone to put on their own page: one line of HTML, no account, no permission, no attribution beyond a credit line.