This is an old project I coded when I was 13. Enjoy!
This Sudoku solver solves most Sudokus in under a second! Click on a field to edit it. To navigate you can use the WASD or arrow keys, and to delete an entry press BACKSPACE. The program automatically detects known errors and warns you before solving, but if you enter a Sudoku with multiple solutions, it takes the first best one. To enter a new Sudoku you have to reload the page.