Quiet Candidates

Deduction Ripples: After reducing a blank to one value, send a ripple through its row, column, and region. Peer candidate lists update, revealing new singletons to propagate.

Each blank begins with candidates 1–4. Select a cell and toggle candidates off until every blank has one remaining value and all Sudoku units are valid. Erase restores all candidates. This is an elimination-only deduction exercise.

Tap or click the controls. Keyboard: Tab and Enter/Space operate every button; arrows/WASD move where available, R restarts, Z undoes calm puzzles.

Mistakes remain revisable. Unlimited undo and restart recover deadlocks.