A sudoku puzzle can be very easy, extremely hard, or somewhere in between, depending on the techniques required to solve it. This page estimates the difficulty level of a given puzzle based on the difficulty of the strategies that must be used to solve it. Enter a puzzle string below (see the main sudoku page and look above the puzzle for an example) and click Grade Puzzle to find out the estimated difficulty level.

### Sudoku Difficulty Estimator

The puzzle string must be 81 characters long. Your string was 80 characters long. Please try again.

Enter a sudoku string (see example):