What Is Key9 Sudoku?

Key9 Sudoku is DaySudoku’s daily opening challenge. You solve nine marked cells first, then unlock the full Sudoku board for the day.

The Key9 idea

Every DaySudoku puzzle has exactly nine Key9 cells. Across those marked cells, the answer digits are 1 through 9 exactly once. The goal is to place all nine numbers before reaching 9 misses.

How to play Key9

Start by selecting a marked cell on the Sudoku board. Then place one of the numbers 1 through 9. Correct numbers lock into the board. Wrong placements count as misses, and the official Key9 attempt ends at 9 misses.

What happens after Key9

When you unlock Key9, the nine solved cells stay on the board and the full Sudoku becomes available. If you miss Key9, you can still keep solving as practice or continue into the full Sudoku.

Why Key9 makes daily Sudoku faster and more shareable

Key9 gives the daily puzzle a compact first goal. It keeps the start quick, makes progress easy to understand, and gives DaySudoku a result that is distinct from a standard online Sudoku board.

Play today’s Key9 Sudoku

Play today’s Key9 Sudoku, or learn more about DaySudoku’s free daily Sudoku puzzle online.