Fill the grid with the digits 1 to 9. Each row, column, 3x3-box and diagonal will have exactly one of each digit. In green cells can only be even digits. In yellow cells can only be odd digits. If two orthogonally or diagonally cells are connected with a red line then the numbers in these cells are consecutive.

Fill in the grid so that every row, every column, every 3 x 3 box and both diagonals contain the digits 1 through 9. There are no neighbouring cells with consecutive digits in rows or columns.

Fill the grid with the digits 1 to 8. Each row, column, 3x3-box and coloured region has exactly one of each digit. One cell is empty. There are no consecutive neighbouring cells.

Fill in the grid so that every row, every column, and every 3 x 3 box contains the digits 1 through 9. There are no neighbouring cells with consecutive digits.

Fill in the grid so that every row, every column, and every 3 x 3 box contains the digits 1 through 9. There are no neighbouring cells with consecutive digits.

Fill in the grid so that every row, every column, and every 3 x 3 box contains the digits 1 through 9. There are no neighbouring cells with consecutive digits.

Fill in the grid so that every row, every column, and every 3 x 3 box contains the digits 1 through 9. All neighbouring cells with consecutive digits have a colored border between.

Fill in the grid so that every row, every column, and every 3 x 3 box contains the digits 1 through 9. All neighbouring cells with consecutive digits have a colored border between.

Fill the grid with the digits 1 to 9. The digits represent the height of the skyscraper in each cell. Each row, column and 3x3-box has exactly one of each digit. The clues along the edges tell you how many skyscrapers you can see from that vantage point. The digit in a circle is the sum of the digits which are marked with its arrow.

Fill in the grid so that every row, every column, and every 2 x 3 box contains the digits 1 through 6. The digit in a circle is the sum of the digits which are marked with its arrow.