Hitori

A clean, number‑based logic puzzle. Shade out extra copies of numbers so that every row and column has only unique values in the cells that remain white.

Click a cell to shade it (remove it). Click again to circle it (keep it white). Click a third time to clear your mark.

Try to leave exactly one copy of each number in every row and column, with all white cells connected and no black cells touching side by side.

What is Hitori?

Hitori is a Japanese logic puzzle played on a grid of numbers. Your goal is to shade (remove) some cells so that the remaining white cells follow a small set of strict rules.

How to play

In each row and each column, every number must appear at most once among the white (unshaded or circled) cells.
Shade cells to remove extra copies. Shaded cells are treated as black blocks and do not count when checking for duplicates.
Shaded cells cannot touch horizontally or vertically. They may touch diagonally.
All white cells must stay connected as one group via side‑to‑side moves. The white region cannot split into separate islands.

Controls

Click a cell: shade it (mark as removed).
Click again: circle it to mark it as definitely white.
Click a third time: clear the cell back to undecided.
Use the Reset puzzle button to start from a fresh grid.

Beginner tips

Look for rows or columns with many copies of the same number; at least one of them must be shaded.
Whenever shading a cell would force two black cells to touch, that cell probably needs to stay white.
Keep an eye on connectivity: avoid creating isolated white islands as you shade cells.