Easy Outside Sudoku

Clues outside the grid give the first three digits encountered in that row or column — but not their order.

Easy Medium Hard Expert

New to Outside Sudoku? Digits outside the grid must land in the nearest three cells of that row or column. Start here.

31
27
94
96
52
31
26
18
49
97
64
38
47
52
36
95
37
68
1
9
5
3
2
8
4
2
7
3
8
6
9
7
5
1
9
4
8
7
3
3
8
4
2
9
4
1
7
3
8
3
8
4
6
3
9
2
28
17
65
12
87
59
73
45
12
27
94
65
54
18
69
75
42
68
Mistakes
0/3
Score
-
Time
00:00
Try Medium Outside Sudoku →
Progress0%

What is Outside Sudoku?

Difficulty
★★★☆☆
3/5
Constraint Type
Outside Clues
Typical Givens
28–36 given + 4×9 outside clues
Avg. Solve (Easy)
8 min

Solving Techniques for Easy Level

Technique Description Level
Clue-Zone Mapping Each outside digit must appear in the nearest 3 cells of its row or column. Map all outside clues to their zones immediately. Beginner

Ready to go deeper? Try Medium Outside Sudoku to unlock Intermediate techniques.

Techniques to Master at Easy

  • Last Remaining Cell technique — Each outside clue confines its digit to a three-cell window — if two window cells are blocked by row or box logic, the clue digit's last legal cell is found.
  • Notes in Sudoku — Pencil each clue digit into its three-cell window before solving — when three clues stack on one window, those three cells are fully claimed and everything else is excluded.

Average Solve Time by Difficulty

Easy
8 min
Medium
18 min
Hard
36 min
Expert
65 min
Want a full walkthrough of rules, strategies, and solving steps? How to Play Outside Sudoku →

Related Variants

Skyscraper Sudoku

The next step in border-clue logic — outside numbers become visibility counts that constrain entire row orderings.

Sandwich Sudoku

Border clues with arithmetic teeth: each one is the sum of the digits trapped between 1 and 9.

Killer Sudoku

Moves the clue layer inside the grid as summed cages — a natural graduation from window placement to sum deduction.

Frequently Asked Questions — Easy Outside Sudoku

What is Outside Sudoku?
Outside Sudoku is a Sudoku variant where digit clues appear outside the grid along each row and column. Each outside digit must appear within the nearest three cells of that row or column — the first box from that edge. Standard Sudoku rules still apply.
Where exactly must the outside clues go?
A clue on the left side of a row must appear in that row's first three cells (columns 1–3). A clue on the top of a column must appear in that column's first three cells (rows 1–3). Right-side clues go in the last three cells of the row; bottom clues go in the last three cells of the column.
Can the same digit appear as both a left clue and a top clue?
Yes. A digit can appear as an outside clue on multiple sides. Each clue independently constrains only its own row or column — it doesn't create a direct link between two sides.
How do I start solving easy Outside Sudoku?
Find rows or columns with two or three outside clues — those clues must all fit into just three cells, so the set of possibilities is very small. Use standard box uniqueness to narrow down which cell each clue digit occupies.
How is Outside Sudoku different from regular Sudoku?
Regular Sudoku gives you digits inside the grid. Outside Sudoku gives you almost no digits inside — instead, clue digits appear on the border and must land within the nearest three cells of each row or column. You're working from the edges inward.

More questions? See the full Outside Sudoku guide.