Extreme Sudoku

How to solve Extreme Sudoku

What makes a puzzle Extreme is the hardest step it needs. Most often that step is ALS-XZ (86%) or Unique Rectangle (12%).

Extreme puzzles need the deepest patterns in our app. Most are decided by ALS-XZ, which links two almost locked sets through a number they share, and the rest mostly by a Unique Rectangle, which uses the fact that the puzzle has only one solution. Expect to spend a while on one step.

Learn ALS-XZ step by step →

Extreme Sudoku: questions and answers

How many numbers do Extreme puzzles start with?

Extreme puzzles here start with 26 to 28 of the 81 squares filled in, most of them with 26.

Do Extreme puzzles need guessing?

No. Every puzzle has exactly one solution, and the hint engine of our app solves each one with logic alone, one technique at a time.

Can I get a hint while I play?

Yes. Hint names the technique the next step needs and shows it on your board one step at a time, with the same hint engine our app uses.

What comes after Extreme?

Extreme is the hardest of the six levels.

All six levels

• Easy SudokuNearly Complete (95%)
• Medium SudokuHidden Single (100%)
• Hard SudokuPointing Pair (60%), Naked Pair (18%), Box/Line Reduction (13%), or Hidden Pair (6%)
• Expert SudokuSkyscraper (55%), Y-Wing (30%), or Empty Rectangle (6%)
• Master SudokuXY-Chain (59%), W-Wing (28%), X-Chain (6%), or XYZ-Wing (5%)
• Extreme SudokuALS-XZ (86%) or Unique Rectangle (12%)

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