Sudoku 18x18 num: 531 (Level: hard)
5
I
2
9
H
C
3
6
G
D
C
4
A
1
E
2
8
G
F
3
8
I
9
A
A
H
E
6
F
9
D
2
I
B
6
7
H
C
A
2
9
A
C
G
A
C
E
F
B
3
7
D
2
9
5
E
1
B
5
9
2
F
6
C
1
E
F
D
9
D
A
C
I
5
B
3
7
F
1
7
5
D
C
G
6
I
3
B
5
H
4
5
2
4
D
A
C
B
1
1
6
G
I
C
H
4
H
C
6
E
G
8
2
5
578I29HC4D1AB3F6GE
HDC4A16GFE3B29I587
6EGFB358I792A14HCD
C4AH1EGB6F739D582I
GFB637825ID91EHCA4
8I259DCAH4E1376GBF
2598D4A1CHFE7IGB36
AH1CEFB3G6I7D48295
B63G7I29854DEFCA1H
3G7BI59D28H4F6A1EC
1CEAF637BG5I4H29D8
98D24H1EAC6FI5B37G
D249HCEF1AG65837IB
7BI358D492CH6G1EFA
EAF16G7I3B85HC9D42
I357824HD9ACGBEF61
F16EGBI57328CAD4H9
49HDCAF6E1BG827I53
Sudoku 18x18
Sudoku 18x18 is a bold expansion of the classic puzzle, stretching the challenge across a grid of 18 rows and 18 columns. The board is organized into 18 regions of 3x6 cells, and, as always, each number must appear only once in every row, column, and region. Instead of the usual nine symbols, you'll work with the numbers 1 through 18, which makes the puzzle broader and more dynamic. The larger variety of digits creates more possibilities but also more patterns to discover, rewarding players who enjoy patience, observation, and logical deduction. It's not about racing to the end but about carefully building the solution piece by piece.
Every puzzle begins with a set of starting numbers scattered across the grid. These initial clues provide the foundation for your reasoning, helping you eliminate candidates and trace the flow of logic throughout the puzzle. There is always a single unique solution, reached without guessing, making every step meaningful. This 18x18 version is ideal for players who already feel comfortable with formats like 12x12 or 16x16 and are ready to explore something even more expansive. It offers a fresh mental workout that improves concentration, strengthens analytical skills, and builds persistence. Solving an 18x18 Sudoku is like assembling a giant mosaic-each correct placement contributes to the beauty of the completed board.