How to play Mini Kropki Sudoku

These four mini Kropki Sudoku puzzles use a 4×4 grid. Put the digits 1 to 4 once in every row, column and 2×2 box. Printed clues stay fixed.

Read the dots

A white dot means the two neighbouring digits differ by one. A black dot means one digit is twice the other. Every possible dot is shown: without a dot, the digits are neither consecutive nor double.

1 and 2 satisfy both dot rules. This set shows a black dot for that pair; a black dot does not forbid consecutive digits.

Place a number

Choose a square, then 1, 2, 3 or 4. Clear square removes your entry. Marked squares break a row, column, box or dot rule; a partly filled board is not complete.

Hints

Each puzzle has one solution. Hint clears a wrong entry before filling an empty square. Undo takes back a hint or number. Restart keeps the printed clues.

Keyboard

Tab to a square and press Enter or Space to select it. Arrow keys move between squares. While a square has focus, type 1–4 or use Delete or Backspace to clear it.

Your progress

Each puzzle keeps its own moves in this browser. Choose another puzzle to revisit it. Undo also takes back a hint or restart. If saving fails, the notice gives the reason and a recovery action. Damaged saved data is kept until you explicitly replace it.