How to Solve Sudoku

1. Start With the Most Filled Areas

Rows, columns, and 3x3 boxes with fewer empty cells make candidates easier to narrow down.

2. Find Single Candidates

After removing digits already present in the same row, column, and box, fill any cell with only one remaining candidate.

3. Look for Hidden Singles

If a digit has only one possible position inside a row, column, or box, that digit is confirmed even when the cell has other candidates.

4. Clean Up Notes

After placing a confirmed digit, remove that digit from notes in the same row, column, and box. SudokuDay automatically clears related notes after correct entries.

5. Change Your View When Stuck

Do not stay in one box too long. Pick one digit and scan the whole board for the next possible position.