Expert Little Killer Sudoku
Clues outside the grid give diagonal sums — digits may repeat along the arrow. Combine diagonal enumeration with classic Sudoku logic. Free online.
Expert Little Killer Sudoku. The hardest puzzles on the site — every placement follows from precise logical reasoning. No guessing.
4
8
3
9
5
8
7
2
1
4
6
9
5
5
4
3
3
8
2
9
3
2
1
Diagonal Clues
↘
from (1,1):
49
(9 cells)
↘
from (1,2):
41
(8 cells)
↘
from (1,3):
34
(7 cells)
↘
from (1,4):
32
(6 cells)
↘
from (1,5):
26
(5 cells)
↘
from (1,6):
27
(4 cells)
↘
from (1,7):
15
(3 cells)
↘
from (1,8):
8
(2 cells)
↘
from (2,1):
38
(8 cells)
↘
from (3,1):
30
(7 cells)
↘
from (4,1):
28
(6 cells)
↘
from (5,1):
19
(5 cells)
↘
from (6,1):
24
(4 cells)
↘
from (7,1):
18
(3 cells)
↘
from (8,1):
8
(2 cells)
↙
from (1,2):
10
(2 cells)
↙
from (1,3):
19
(3 cells)
↙
from (1,4):
24
(4 cells)
↙
from (1,5):
14
(5 cells)
↙
from (1,6):
33
(6 cells)
↙
from (1,7):
41
(7 cells)
↙
from (1,8):
46
(8 cells)
↙
from (1,9):
41
(9 cells)
↙
from (2,9):
37
(8 cells)
↙
from (3,9):
32
(7 cells)
↙
from (4,9):
31
(6 cells)
↙
from (5,9):
25
(5 cells)
↙
from (6,9):
17
(4 cells)
↙
from (7,9):
16
(3 cells)
↙
from (8,9):
8
(2 cells)
What is Little Killer Sudoku?
Difficulty
★★★★☆
4/5
Constraint Type
Outside Clues
Typical Givens
0–6 given digits
Avg. Solve (Expert)
88 min
Solving Techniques for Expert Level
| Technique | Description | Level |
|---|---|---|
| Diagonal Enumeration | For each clue, enumerate all combinations of N digits (allowing repeats, 1–9) that sum to the clue value. | Beginner |
| Repeating Digits Allowed | Unlike Killer cages, Little Killer diagonals can repeat digits as long as standard row/column/box uniqueness is preserved. | Beginner |
| Short Diagonal Logic | A 1-cell diagonal directly gives that cell's digit. A 2-cell diagonal with clue C has limited pairs — enumerate them immediately. | Intermediate |
| Cross-Diagonal Intersection | When two diagonals share a cell, the shared cell must satisfy both sum constraints simultaneously. | Advanced |
| Row/Column Interaction | A diagonal cell belongs to a row, column, and box — combine Little Killer sum constraints with standard uniqueness rules. | Intermediate |
Average Solve Time by Difficulty
Easy
14 min
Medium
28 min
Hard
55 min
Expert
88 min
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Frequently Asked Questions — Expert Little Killer Sudoku
More questions? See the full Little Killer Sudoku guide.