Expert Sudoku
The toughest Sudoku tier - 22 to 26 clues that demand X-Wings, swordfish, and chain-based logic.
How to play Expert Sudoku
- 1 Fill each row with the digits 1-9, with no repeats.
- 2 Fill each column with the digits 1-9, with no repeats.
- 3 Fill each 3x3 box with the digits 1-9, with no repeats.
- 4 Use full candidate tracking and advanced techniques - every expert puzzle has a single unique solution reachable by logic alone.
Why play Expert Sudoku?
Expert Sudoku is the pinnacle of pure logical puzzle solving. With as few as 22 to 26 starting clues, every elimination matters and a single misplaced digit can take twenty minutes to unwind. Solving expert boards trains long-form planning, chain visualization, and the discipline to maintain accurate candidate lists across a forty-minute session. It is the level where competition solvers spend most of their training time, and where a single completed grid is its own substantial accomplishment.
Tips to solve Expert Sudoku
- Keep a complete candidate list for every empty cell from move one. Expert puzzles are unforgiving to lazy pencil-marking.
- After every placement, propagate eliminations through the affected row, column, and box before searching for the next move.
- Hunt for X-Wings: two rows where a candidate is locked to the same two columns let you eliminate that digit from those columns elsewhere.
- Look for XY-Wings and XYZ-Wings - a pivot with two candidates and two compatible wings often forces a critical elimination.
- When truly stuck, swordfish (a three-row generalization of X-Wing) and remote pairs frequently unlock the chain.
- Take breaks. Expert puzzles reward patience - a fresh look often surfaces the pattern you missed.
Expert Sudoku - frequently asked questions
What is expert Sudoku?
Expert Sudoku refers to 9x9 Sudoku puzzles with roughly 22 to 26 starting clues. Solving requires chain-based techniques like X-Wings, swordfish, XY-Wings, and remote pairs in addition to the standard scanning and pencil-mark methods.
Is expert Sudoku solvable without guessing?
Yes. Every expert Sudoku on SudokuW has a single unique solution reachable by pure logic. If you find yourself guessing, an advanced technique is available that you have not spotted yet.
How long does an expert Sudoku take?
Expert Sudoku typically takes thirty minutes to over an hour. A particularly difficult expert puzzle can occupy a full session.
Do I need pencil marks on expert?
Absolutely. Full candidate tracking is non-negotiable on expert. Use the notes mode and update it after every placement.
Is expert Sudoku free?
Yes. Expert Sudoku is completely free, with unlimited new boards and no sign-up.
What is the difference between hard and expert Sudoku?
Hard Sudoku requires advanced eliminations like pointing pairs and X-Wings. Expert Sudoku takes it further - you will routinely need swordfish, XY-chains, and other chain-based logic. Expert boards also have fewer starting clues, which makes early-game scanning sparser.
Try other difficulty levels
Step back to hard Sudoku for a slightly gentler challenge, or take on the daily.