How to play Futoshiki
Fill each empty square with a number from 1 to 4. Every row and every column needs all four numbers, and every comparison sign must agree.
One of each number
A row containing 2, 4, 1 and one empty square is missing 3. The same rule applies down a column. There are no smaller boxes to complete.
Underlined numbers are givens. They stay fixed while you solve.
The narrow end points to the smaller number
1 < 3 is true. 4 < 2 is not. A vertical sign follows exactly the same rule: its narrow tip points toward the smaller square, above or below.
If a square is on the smaller side of a sign, it cannot contain 4. If it is on the larger side, it cannot contain 1.
Follow a chain
On a 4×4 board, four increasing squares can only be 1 < 2 < 3 < 4. For a shorter chain, combine its limits with the numbers already used in the same row and column.
A square with no touching sign still follows the row and column rules.
Choose a square, then a number
Tap a square and use the number buttons. With a keyboard, use arrows to move and 1–4 to enter. Backspace, Delete or 0 erases an entered number. Home and End move to the first or last square in the row.
A dashed border and ! mark a repeated number or a broken comparison. The message explains the conflict. An entry can still be wrong without breaking an immediate rule.
Undo restores the previous board. Clear entries asks before clearing your numbers and can also be undone. Reveal a cell checks the unique solution: it corrects an incorrect filled square before revealing an empty one.
Daily and practice
Orderfern has 24 original 4×4 puzzles. Daily selects one by UTC date and repeats after 24 days. Your saved daily puzzle stays available across midnight and when you reopen the page. Choose Play today’s puzzle when you are ready to replace the previous daily.
Practice chooses another puzzle from the same finite collection. Daily and practice entries are saved separately in this browser. If a saved record is damaged, it is kept until you explicitly confirm replacing it.