Shade squares so no number repeats in a row or column, shaded squares never touch, and the white squares stay joined
Hitori is a logic puzzle on a square grid full of numbers. Some numbers appear more than once in the same row or column, and your job is to shade squares to remove the repeats. Three rules decide which: when you are done, no number may appear twice among the white squares of any row or column; two shaded squares may never touch side by side; and all the white squares must still form one connected group. Only a square whose number repeats can be shaded. Ours builds a new grid each time in three sizes, and a solver checks every legal shading before you see it: the puzzle is used only when exactly one exists.
Pick a level: easy is a 5×5 grid, medium 6×6 and hard 8×8. The numbers run from 1 up to the grid size.
Press New puzzle. Tap a square once to shade it, again to circle it (a reminder that it stays white), and a third time to clear it. The Shade, Keep and Clear buttons do the same for the selected square.
Shade squares until no number repeats among the white squares of any row or column.
Never shade two squares that share a side. Touching at a corner is fine.
Keep every white square joined to the others through white squares; shading must never cut the grid in two.
With Show clashes on, touching shaded squares, a shaded square whose number does not repeat, and two circled squares with the same number in a line turn red. The line under the grid counts the white squares that still repeat.
On a keyboard, move with the arrow keys, press X to shade, O to circle, Space to cycle, Backspace to clear and Ctrl+Z to undo. The puzzle ends as soon as all three rules hold.
Rule-based deduction with several constraints at once. Every decision has consequences in two directions: shading a square forces its four neighbours to stay white, and keeping a square white forces every other copy of its number in that row and column to be shaded. Following those chains, and spotting when a shading would cut off part of the grid, trains systematic reasoning, visual scanning along rows and columns, and the discipline of only committing to what the rules force. Another logic game to try next: Binary Puzzle. For a planning puzzle with no grid at all, try the Tower of Hanoi.
A number that appears nowhere else in its row and column always stays white. Circle it to keep it out of the way.
In a run of three equal numbers side by side (5 5 5), the middle one stays white and both ends are shaded.
Two equal numbers with one square between them (4 x 4): at least one of the 4s must be shaded, so the square in between must stay white, or two shaded squares would touch.
Every shaded square's four neighbours are white. Circle them straight away; it often shows the next repeat to shade.
In a corner, if shading one square would wall in its corner neighbour, that shading is impossible.
When stuck, pick a repeated pair, assume one is shaded, and follow the consequences; if they break a rule, the other one is shaded instead.
Hitori is a logic puzzle where you shade squares of a number grid so that no number repeats in any row or column among the unshaded squares, no two shaded squares share a side, and all unshaded squares stay connected.
Hitori is Japanese and is usually translated as alone or one person: each number should be left alone in its row and column.
Yes. Only shaded squares that share a side are forbidden. Corner to corner is allowed, as long as the white squares around them stay connected.
No. Only a square whose number appears again in its row or column may be shaded; the game marks any other shading as a clash. This is the usual hitori convention and it is how every puzzle here keeps a single answer.
Yes. The generator picks a random shading that already obeys the touching and connection rules, fills the white squares so they never repeat, and gives each shaded square a number that repeats one in its row or column. A solver then searches every legal shading; the grid is shown only if it finds exactly one.
Grid size: easy is 5×5, medium 6×6 and hard 8×8, with more of the grid shaded on bigger boards. Each level keeps its own best time.
It is free with no sign-up. Your best time per level, the number of puzzles you have solved and the Show clashes setting are saved in this browser only.