All games / Hitori
Hitori
A little ink. One clear path.
Tap a square to use the selected Shade or Mark white tool. Ordinary white and circled white both count as white. Arrows select; Enter shades, Space marks white, Delete clears. U/Y undo/redo, H hints, C checks, P pauses. Fresh puzzle · Puzzle .
Your achievements 0 / 8
How to play Hitori
Shade some numbers black so that the remaining white numbers do not repeat in any row or column. Black squares must never share an edge, and all white squares must stay connected through shared edges. The three rules work together.
Distinct, apart, connected
Look for repeated numbers in a row or column and decide which to shade. You do not fill or change the numbers, and a white row does not need to contain every number. Diagonally touching black squares are allowed, but even diagonal black arrangements can cut white squares off from the rest. Check the whole white path.
Ordinary unmarked squares count as white, just like circled white squares. You win as soon as all three rules fit; you do not need to circle every white number. At least one white square must remain.
Three clear square states
Choose Shade, then tap a square. An ordinary white square becomes black; black returns to ordinary white. Shading a circled square first removes its circle, leaving ordinary white. Tap again to shade it.
Mark white adds or removes an optional circle on an ordinary white square. On black, Mark white first clears the shading to ordinary white. Clear removes either kind of mark. Circles are your reminders, not fixed clues.
Amber edges identify repeated white numbers that still need work. They are normal on an unfinished puzzle. Red highlights identify current black adjacency or disconnected white cells. An unfinished or mistaken position does not end the game: you can change a mark, Clear or Undo.
A little help, honestly labelled
Hint records help immediately without changing a square. It may explain a concrete rule deduction, such as keeping the neighbour of black white, point out a conflicting black pair, or explicitly check a chosen mark against the verified unique completion. When it offers a mark from the verified solution, the message calls it a reveal rather than a simple deduction.
Apply suggested mark uses the ordinary Shade or Mark white actions. Changing an opposite mark can first clear it, following the same rules as your own input. A white suggestion may add a circle, but the circle itself is optional for completion.
Check describes the current duplicate, adjacency and connectivity conditions. It does not promise that a partial position has a finishing route. Asking for Hint or Check counts as help even when it only diagnoses a problem. Unmarked white squares are still undecided for future reasoning; the game does not treat every unmarked square as a locked white choice.
Keep the reasoning, keep your progress
Undo and Redo revisit marks. A new edit clears the Redo branch. Restart returns the same fixed number grid to an unmarked state as practice. New puzzle or a size change asks before replacing your current work. Help, first results and practice history stay recorded after Undo, Restart, reload or another variation of the same original.
This edition contains 48 original puzzle bases, 24 each in 5×5 and 6×6. Each base has one verified shading solution. Rotations, reflections and number-label variations preserve its rules. Originals can recur; your collection counts each original only once. Grid size is not a standardized difficulty rating.
Eight small milestones
Earn stars for a real first shading action, your first completed original, each grid size, completing both sizes, a fresh first clear, and collections of three and ten originals. The first shading star recognises an action; it does not certify that the chosen shade is correct.
A fresh-clear star requires your first clear of an original before Hint, Check, Undo or Restart has been used on that original. Assisted clears still join your collection. Replaying a completion does not add duplicate wins, and earned achievements stay earned.
Comfortable controls
Tap a square to use the selected tool. With a keyboard, arrows select a square, Enter or B performs Shade, Space or W performs Mark white, and Backspace, Delete or 0 clears it. Home and End move to the row edges. Right-click is another Mark white option. The large Shade square or Mark white button applies the current tool to the selected square.
U or Ctrl+Z undoes; Y or Ctrl+Shift+Z redoes. H asks for Hint, C checks, P pauses, N asks for a new puzzle and R asks to restart. Escape closes a panel or returns from full screen.
Full screen gives the notebook more room. An accepted edit opens it automatically on a small viewport; a passive saved reload stays on the page. The grid keeps its own space while long hints and tools scroll separately. Pause hides the numbers and marks and stops active time. Sound starts off, celebrations stay away from the board, and motion follows your browser preference.
Saved in this browser
Your current grid, shades, circles, selected square, chosen tool, active time, sound preference and achievements save when browser storage is available. A returning active puzzle waits for Resume. A persistent warning explains when saving is unavailable; keep that page open because its in-memory progress may be lost after leaving. No account is needed.