SudokuHard

Hard Sudoku — Puzzle 21

981
1924
67
8794
435
36
546
57
248

How to play

Fill every row, every column and every 3 by 3 box with the numbers 1 to 9, using each number once.

This puzzle has 26 given numbers and exactly one solution, so it can always be finished by reasoning alone.

359784612
817692453
462135789
283576194
946213875
175948326
538421967
694857231
721369548