Iron Sudoku is 100% free to play. Anyone can play the daily puzzles and chat with other players from around the world. If you want to take advantage of Iron Sudoku's many extra features, you can upgrade to a Pro account at any time.
NOTE: Iron Sudoku requires that you use a modern browser in order to function properly.
(A few popular examples)
|Internet Explorer 6.x (or greater)||Yes|
|Firefox 1.x (or greater)||Yes|
|Safari 1.x (or greater)||Yes|
|Netscape 6.x (or greater)||Yes|
|Opera 8.x (or greater)||Yes|
|Internet Explorer 5.x||No|