😤 Hard Sudoku #1
27 clues • Unique solution guaranteed
4
4
6
2
9
2
8
7
6
3
7
1
4
1
2
1
2
6
5
8
3
9
1
5
4
8
7
Given
Puzzle Controls
💡 Solving Tips
- • Start with rows/columns that have the most numbers
- • Look for numbers that can only go in one cell
- • Check each 3×3 box for missing numbers
- • Use pencil marks for candidates when printing
Puzzle Details
Difficulty:Hard
Given Clues:27
Empty Cells:54
Puzzle ID:696437405
About Hard Sudoku Puzzle #1
This hard Sudoku puzzle offers an advanced challenge demanding complex strategies. With 27 given clues, this puzzle is guaranteed to have exactly one unique solution.
How to Solve
Basic strategies for solving this Sudoku puzzle:
- Scanning: Look for numbers that can only go in one cell
- Marking Candidates: Write possible numbers in empty cells
- Elimination: Remove candidates based on filled numbers
- Pattern Recognition: Look for pairs, triples, and other patterns
- X-Wing & Swordfish: Advanced pattern-based techniques
- Coloring & Chains: Complex logical deduction methods
Puzzle Features
- Difficulty: Hard (25-30 clues)
- Given Clues: 27 numbers provided
- Unique Solution: Guaranteed single valid solution
- Algorithm Generated: Created using backtracking algorithm
- Printable: Download as PDF for offline solving
Tips for Success
Start by scanning the grid for easy placements. Look for rows, columns, and 3×3 boxes that are nearly complete. Mark potential candidates in pencil if printing, or use the show solution toggle if you get stuck.
This puzzle is generated using a sophisticated backtracking algorithm that ensures a valid Sudoku grid with exactly one solution. The clue placement is randomized while maintaining solvability, providing a fresh challenge every time.