All games / Futoshiki
Futoshiki
Small signs. Satisfying logic.
Fill 1–4 or 1–5 once in each row and column. Every inequality must fit; there are no Sudoku boxes. Tap a square and use the number pad, or type a number. Arrows move, Shift+number adds a note, Backspace erases. U/Y undo/redo, H hints, C checks, P pauses. Fresh puzzle · Puzzle .
Your achievements 0 / 8
How to play Futoshiki
Fill every square with a number from 1 to 4 on a 4×4 grid, or 1 to 5 on a 5×5 grid. Each row and each column must contain every number exactly once. Every displayed inequality must also be true. There are no Sudoku boxes.
Follow the pointed end
The pointed end of each sign faces the smaller number: 1 < 3 and 3 > 2. The same rule applies vertically. A sign shaped like ∧ points to the smaller number above it; ∨ points to the smaller number below it. No sign between two squares adds no extra restriction.
Starting numbers are fixed in ink. Your entries use a different shade. Conflicting row or column duplicates and filled inequalities are highlighted. A partly filled grid can have no visible conflict and still contain a choice that cannot finish the puzzle.
A notebook for your deductions
Select any square, then choose a number. Notes switches the number pad to pencil marks: choose the same note again to remove it. Notes belong in empty editable squares. Entering a full number replaces its notes; Erase clears your number or all notes in that square. Notes are reminders and do not count as answers.
Undo and Redo revisit entries and notes. A new edit clears the Redo branch. Restart returns to the same starting clues as practice. New puzzle or a size change asks before replacing your current grid. Neither operation takes away achievements you have already earned.
Help that explains its limits
Hint does not fill a number automatically. It may point out a conflict, explain a forced value from row, column and inequality restrictions, or explicitly offer a value from the verified unique solution. A solution reveal is labelled as a reveal. Choose Fill suggested number if you want to enter an offered value, or keep reasoning on your own.
Check tests your current entries against the visible row, column and inequality rules. A clear check does not certify that the partial grid can be completed. Hint may also identify an entry that differs from the verified solution, even when that entry has no visible conflict.
Asking for Hint or Check counts as help immediately, including when it diagnoses a problem without filling anything. Help and practice remain recorded after Undo, Restart, reload, or another variation of the same original puzzle.
Two sizes, original puzzles
This edition includes 48 original puzzle bases: 24 in each size. Each base has one verified solution. Rotations, reflections and reversing the number order provide variations while preserving the rules. A familiar original may appear again; your collection counts each original only once. The size labels describe the grid, rather than promising a standardized difficulty rating.
Eight small milestones
Earn stars for a completed row with no visible conflict, your first solved puzzle, a 4×4 clear, a 5×5 clear, a clear in both sizes, a fresh first clear, and collections of three and ten original puzzles. The fresh-clear star requires your first clear of an original before using Hint, Check, Undo or Restart on it. Assisted clears still join your collection. Replaying a finish does not add duplicate wins.
Comfortable controls
Tap or click a square and use the number pad. On a keyboard, type a number; Shift+number toggles a pencil note. Arrow keys move between squares, Home and End move to the row edges, and Backspace, Delete or 0 erases. N toggles Notes, U or Ctrl+Z undoes, Y or Ctrl+Shift+Z redoes, H requests a hint, C checks, P pauses and R asks to restart. Escape closes a panel or returns from full screen.
Full screen gives the notebook more room. On a small viewport, your first edit opens that view automatically; simply reloading a saved puzzle does not. In a short landscape view, the grid stays in place while the tools and explanations scroll separately. Pause hides numbers and notes and stops active time. Sound starts off, celebrations stay clear of the grid, and motion follows your browser preference.
Keep your place
Your current puzzle, entries, notes, selected square, active time, sound preference and achievements save in this browser when storage is available. A returning active puzzle waits for Resume. If saving is unavailable, a persistent message explains that your in-memory puzzle may be lost after leaving the page. No account is needed.