How is this different from normal Sudoku?

Only by the diagonals. The usual row, column and box rules still apply, and the diagonals add two more groups of nine.

Can there be more than one answer?

No. Each puzzle is checked by a solver that confirms it has exactly one solution.

Yes, on this device. You can leave and come back to the same grid.

Classic Sudoku with one extra rule: both long diagonals must also hold each digit from 1 to 9 exactly once. A fresh puzzle every day.

X Sudoku

0% · Getting ready

A real run of the game, recorded with captions and no sound.

Fill the grid so every row, column and 3 by 3 box contains each digit from 1 to 9 once.
The two diagonals, shown with a light shade, must also contain each digit once.
Tap a cell, then a number. Use Notes to pencil in candidates and Erase to clear a cell. Conflicts turn red.
Every puzzle has exactly one solution and can be solved by reasoning, with no guessing. Daily is the same for everyone; Easy, Medium and Hard give new puzzles.

Controls: mouse, touch or keyboard. Made by CalcoTools.

The diagonals cut across many boxes. Check them first, since a digit missing from a diagonal often has only one place left.
The centre cell belongs to both diagonals, so it sees more cells than any other. Its candidates fall fast.
Use Notes on the diagonal cells. A digit that can only go in one of them is a quick win.
When a digit is placed, look at both diagonals as well as its row, column and box.

How is this different from normal Sudoku?: Only by the diagonals. The usual row, column and box rules still apply, and the diagonals add two more groups of nine.
Can there be more than one answer?: No. Each puzzle is checked by a solver that confirms it has exactly one solution.
Is my daily progress saved?: Yes, on this device. You can leave and come back to the same grid.