Expert Sudoku Online
Expert is our hardest Sudoku level, with the fewest numbers filled in and one solution you can reach by logic.
How do you play Expert Sudoku?
An expert Sudoku gives you very few numbers to start. Fill in pencil notes for the whole grid and keep them correct. Use pairs and pointing again and again to remove notes. Each removed note can open a new single. Work slowly and check each step, because every puzzle has one solution.
Sudoku rules
- The grid has 9 rows, 9 columns and nine 3 x 3 boxes. Some numbers are already filled in.
- Fill every empty square with a number from 1 to 9.
- Each row, each column and each 3 x 3 box must contain every number from 1 to 9 exactly once.
- Every puzzle has exactly one solution, and you can always find the next number by logic.
- A wrong number counts as a mistake. After three mistakes, you can watch a short ad for one more chance.
Expert Sudoku tips
- Complete the pencil notes for the whole grid first. Expert puzzles are very hard to solve without them.
- Check every row, column and box for pairs, then check every box for pointing numbers.
- Go slowly. A wrong number counts as a mistake, and you have three before the puzzle stops.
- Use undo if you spot an error in your notes, and take a hint only when you are fully stuck.
More ways to play Sudoku
Expert Sudoku questions
How do you solve an expert Sudoku?
Fill in notes for the whole grid, then use pairs and pointing to remove notes step by step. Each step can reveal a square with only one number left.
What makes expert Sudoku so hard?
Expert puzzles have fewer numbers filled in and need harder techniques like pairs and pointing, often several times in one puzzle.
Does an expert Sudoku have only one solution?
Yes. Every puzzle here is checked to have exactly one solution and can be solved by logic without guessing.
Is expert Sudoku free to play here?
Yes. It is free with no download and no sign-up, and it never uses real money.
Play something else
More puzzle games →
Number MergeSlide tiles and join equal numbers to reach 2048. Three board sizes, undo, hints and a daily challenge.
Mahjong SolitaireMatch pairs of free tiles to clear the board. Three layouts, hints, undo, shuffle and a daily puzzle. Every deal can be solved.
MinesweeperClear the board without hitting a mine. Four levels, safe first click, hints and a no-guess daily board.
Block PuzzleDrag shapes onto the grid and clear full rows and columns. Three levels, undo, hints and a daily challenge.
Picture PuzzleDrag jigsaw pieces into place to complete colourful pictures. A daily puzzle and four levels from 9 to 36 pieces.
SolitaireClassic Klondike solitaire with draw 1 or draw 3, plus Spider and FreeCell. Undo, hints and a daily deal.