SudokuguroWhat is Extreme Sudoku best for?
Players who want the toughest Sudokuguro mode.
Play Sudoku
Extreme Sudoku Online
Play free extreme Sudoku online with a unique-solution 9x9 puzzle, timer, hints, undo, pause, keyboard controls, and a clean mobile-friendly board.
Last updated
Key Takeaways
- Extreme Sudoku is a free classic 9x9 Sudoku puzzle that runs in the browser.
- This mode removes about 64 cells to create a extreme challenge with one validated solution.
- Timer, hints, undo, erase, pause, and keyboard controls support focused Sudoku practice.
How should I solve extreme Sudoku?
Patient notation, rare patterns, and careful review.
About Extreme Sudoku
This extreme Sudoku mode uses a classic 9x9 grid, unique-solution puzzle generation, timer tracking, mistakes, undo, erase, pause, and limited hints.
The goal is to fill every empty square so each row, column, and 3x3 box contains the numbers 1 through 9 exactly once.
How to Play
Tap a square and choose a number, or use your keyboard. Arrow keys move the selected square, number keys enter values, and Backspace or Delete erases editable squares.
Pause hides the board until you resume. Use hints sparingly so the puzzle remains a logic exercise instead of a guessing loop.
Difficulty Path
Easy and Medium Sudoku build rule fluency. Hard, Expert, Master, and Extreme Sudoku reward cleaner notation and deeper eliminations.
Extreme Sudoku sits in this path as a distinct challenge so players can bookmark the right level and return later.
FAQ
Is extreme Sudoku free on Sudokuguro?
Yes. Sudokuguro is a free browser-based Sudoku game with no account required.
Are Sudokuguro puzzles uniquely solvable?
Sudokuguro validates generated puzzles so each playable board has a unique solution.
Can I play Sudoku with keyboard controls?
Yes. Select a cell, use number keys to enter values, arrow keys to move, and Backspace or Delete to erase.