Skyscrapers puzzle

Each skyscrapers puzzle here is made by our generator: we build a random city, write all the edge clues, then remove clues for as long as the skyscraper puzzle solver still finds exactly one answer.

Rules

• Fill the n by n grid with towers of height 1 to n.
• Each row and each column has every height once.
• A clue outside the grid tells how many towers you can see looking into that row or column. A taller tower hides every shorter one behind it.

Tap a square, then a height. Pencil keeps small candidate heights. A height that repeats in its line turns red, and a clue turns gray when its full line matches it, or red when it does not.

Levels

Easy is 4 by 4 and keeps at least 10 of the 16 clues. Medium (5 by 5) and hard (6 by 6) keep only as many clues as needed for a single answer, so you have to reason from fewer views.

Strategy

• Clue 1: you see one tower, so the tallest one stands right next to the clue.
• Clue n: you see every tower, so the line reads 1, 2, 3 up to n from that side.
• Big clues push tall towers away: with a clue of 4 on a 5 by 5 grid, the 5 cannot be in the first three squares from that side.
• Opposite clues: the tallest tower is seen from both ends, so the clues of a line add up to at most n plus 1.
• Once the tallest towers are placed, the second tallest is usually next, then the rest follow from the row and column rule.

Hints and statistics

Hint explains clue 1 and clue n deductions and squares where only one height is left; when none applies, it reveals a square from the unique answer and says so. Check, Show mistakes, undo and redo, best times and the daily streak work as in our other puzzles. For more number logic, try futoshiki or calcudoku.

Solver tested 6 October 2026. Found a problem? Tell us.

Questions