Medium 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.
Little Killer Sudoku at medium difficulty. Diagonals interact with rows, columns, and boxes — you'll need both sum logic and standard Sudoku technique.
9
1
3
7
8
9
4
5
3
1
6
2
4
6
2
8
6
4
7
1
3
4
2
5
9
7
6
8
4
2
5
1
Diagonal Clues
↘
from (1,1):
45
(9 cells)
↘
from (1,2):
37
(8 cells)
↘
from (1,3):
33
(7 cells)
↘
from (1,4):
32
(6 cells)
↘
from (1,5):
29
(5 cells)
↘
from (1,6):
25
(4 cells)
↘
from (1,7):
19
(3 cells)
↘
from (1,8):
5
(2 cells)
↘
from (2,1):
46
(8 cells)
↘
from (3,1):
18
(7 cells)
↘
from (4,1):
32
(6 cells)
↘
from (5,1):
23
(5 cells)
↘
from (6,1):
29
(4 cells)
↘
from (7,1):
11
(3 cells)
↘
from (8,1):
12
(2 cells)
↙
from (1,2):
6
(2 cells)
↙
from (1,3):
20
(3 cells)
↙
from (1,4):
15
(4 cells)
↙
from (1,5):
19
(5 cells)
↙
from (1,6):
33
(6 cells)
↙
from (1,7):
38
(7 cells)
↙
from (1,8):
47
(8 cells)
↙
from (1,9):
44
(9 cells)
↙
from (2,9):
42
(8 cells)
↙
from (3,9):
22
(7 cells)
↙
from (4,9):
40
(6 cells)
↙
from (5,9):
18
(5 cells)
↙
from (6,9):
24
(4 cells)
↙
from (7,9):
18
(3 cells)
↙
from (8,9):
11
(2 cells)
What is Little Killer Sudoku?
Difficulty
★★★★☆
4/5
Constraint Type
Outside Clues
Typical Givens
0–6 given digits
Avg. Solve (Medium)
28 min
Solving Techniques for Medium 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 |
| Row/Column Interaction | A diagonal cell belongs to a row, column, and box — combine Little Killer sum constraints with standard uniqueness rules. | Intermediate |
Master these, then take on Hard Little Killer Sudoku to learn Advanced techniques.
Techniques to Master at Medium
- Hidden Singles technique — Extreme diagonal sums force big or small digits into the clue diagonal, evicting them from parallel cells of the crossed boxes — scan those boxes for the displaced singles.
- Obvious Pairs technique — A two-cell diagonal summing to 16 or 17 yields {7,9} or {8,9} — instant pairs whose eliminations run through both the row and box of each diagonal cell.
Average Solve Time by Difficulty
Easy
14 min
Medium
28 min
Hard
55 min
Expert
88 min
Want a full walkthrough of rules, strategies, and solving steps?
How to Play Little Killer Sudoku →
Related Variants
Killer Sudoku
The cage version of the same idea: sum clues with a no-repeat rule that makes the arithmetic tighter than on diagonals.
Sandwich Sudoku
Also driven entirely by numbers written outside the grid — sums between the 1 and 9 instead of along diagonals.
Skyscraper Sudoku
Another outside-clue variant, replacing diagonal sums with visibility counts read from the grid's edges.
Frequently Asked Questions — Medium Little Killer Sudoku
More questions? See the full Little Killer Sudoku guide.