Easy Skyscraper Sudoku

Clues outside the grid count how many buildings are visible when looking in from that side (taller buildings block shorter ones).

Easy Medium Hard Expert

New to Skyscraper Sudoku? Each edge clue counts how many digits you can see looking in — start with clues of 1 (first digit must be 9) and 9 (strictly increasing order).

3
2
4
2
1
3
3
4
3
3
2
3
4
2
3
4
1
2
6
5
4
8
3
1
6
3
4
5
1
8
4
5
1
9
7
3
1
9
2
7
3
6
4
5
8
7
9
9
8
7
1
3
6
3
8
2
4
2
2
1
3
4
2
5
3
2
3
3
1
3
4
3
2
4
Mistakes
0/3
Score
-
Time
00:00
Try Medium Skyscraper Sudoku →
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What is Skyscraper Sudoku?

Difficulty
★★★★☆
4/5
Constraint Type
Outside Clues
Typical Givens
4–10 clue values
Avg. Solve (Easy)
12 min

Solving Techniques for Easy Level

Technique Description Level
Clue 1 Forces 9 First A visibility clue of 1 means the first building from that edge must be a 9. All shorter buildings behind it are hidden. Beginner
Clue 9 Forces Ascending Order A clue of 9 means all buildings are visible, so digits are in strictly ascending order from that edge: 1, 2, 3, 4, 5, 6, 7, 8, 9. Beginner

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

Techniques to Master at Easy

  • Last Possible Number technique — A clue of 1 forces 9 into the first cell, and a clue of 2 caps that cell at 8 while bounding everything behind it — visibility maths alone solves many border cells.
  • Notes in Sudoku — Note each row's possible 9-positions from both clues before anything else: 9 is always visible, so the two opposing clues bound it from each side.

Average Solve Time by Difficulty

Easy
12 min
Medium
25 min
Hard
50 min
Expert
80 min
Want a full walkthrough of rules, strategies, and solving steps? How to Play Skyscraper Sudoku →

Related Variants

Outside Sudoku

Both decode digits written around the border — placement windows here, visibility counts there.

Sandwich Sudoku

Another grid solved from the margins, swapping visibility logic for sums between the 1 and the 9.

Little Killer Sudoku

Outside clues turned diagonal: arrows fire sum totals across the grid instead of counting buildings down a line.

Frequently Asked Questions — Easy Skyscraper Sudoku

What is Skyscraper Sudoku?
Skyscraper Sudoku is a Sudoku variant where numbers appear along all four edges of the grid. Each clue tells you how many digits are visible looking into that row or column from the clue's edge — a digit is visible only if it is taller (larger) than all digits in front of it. Standard Sudoku rules still apply.
How does the visibility rule work?
Imagine looking from outside the grid along a row or column. Each digit is a building of that height. A building is visible if no taller building stands between it and your viewpoint. So from the left, the digit in column 1 is always visible, and any later digit is visible only if it exceeds all previous digits.
What does a skyscraper clue of 1 mean?
A clue of 1 means only one building is visible — the first digit in the row or column from that direction must be 9, because 9 is the tallest digit and immediately blocks all others. This is the most constraining single clue in Skyscraper Sudoku.
How do I start solving easy Skyscraper Sudoku?
Start with clues of 1 (the first cell must be 9) and clues of 9 (the row or column must be in strictly increasing order from that direction, so 1,2,3,4,5,6,7,8,9). These two extreme clue values fully determine the arrangement and are the easiest starting points.
How is Skyscraper Sudoku different from Outside Sudoku?
Outside Sudoku places specific digits outside the grid that must appear in the nearest three cells. Skyscraper Sudoku places visibility counts — not digit values — outside the grid. The clue tells you how many digits are visible from that edge, not which digit appears where.

More questions? See the full Skyscraper Sudoku guide.