Make your next move count
Scan a row, column and box together. A number allowed by one row can still be ruled out by the crossing column or box.
Keep notes up to date. When two cells in a unit share the same two candidates, those digits can be removed from the other cells in that unit.
Read an explanation before using another hint. Candidate elimination may reveal no immediate number, but it narrows the next step without guessing.
A position to try
Play and practise
Select a cell, then a number. Use Notes for candidates.
Hints explain one step. Undo is always available while history is kept.
Daily deals use the UTC date and mode, identically in every language.
No account, no installation. Games and personal records stay in your browser.