Skyscrapers
Skyscrapers is a logic puzzle about a city seen from its edges. Fill the grid with towers of height 1 up to the grid's size so every row and column holds each height once. A number outside the grid says how many towers you see looking in from there, since taller towers hide shorter ones behind them.
How to play
Every Skyscrapers puzzle here has exactly one solution and can be solved by logic alone. The grid grows from 4×4 at Easy to 6×6, and the level is set by the hardest technique the puzzle needs.
- Each row and each column holds every height from 1 to the grid size once.
- A clue counts the towers visible from its side; a taller tower hides every shorter one behind it.
- Rows and columns without a clue can show any count.
- The given heights cannot be changed.
Playing on this site
- Select a cell, then type a digit or tap it on the number pad. Arrow keys move the selection.
- Turn on Notes (or press N) to pencil in candidates instead of answers.
- A clue fades once its line is full and right, and turns red if the line shows another count.
- Hint first points out any wrong digits, then names the next technique and shows where it applies before giving anything away.
- Your puzzle is saved in this browser, so you can come back to it later.
Techniques by level
Every technique the solver knows, from easiest to hardest. A puzzle's level is the hardest one it needs.
Easy
- Hidden single
- In the highlighted row or column this digit fits in only one cell.
- From the edge
- Seeing that many towers limits how tall the nearest ones can be: a 1 sees the tallest first, a full count sees them rise one by one.
Medium
- Naked pair
- Two cells share the same two candidates, so those digits leave the rest of their area.
- Hidden pair
- Two digits fit only in the same two cells, so those cells hold nothing else.
- Fitting the views
- Every order of this line that matches both edge counts agrees on the marked cells.
Hard
- Naked triple
- Three cells hold only three digits between them, so those digits leave the rest of their area.
- Hidden triple
- Three digits fit only in the same three cells, so those cells hold nothing else.
- X-Wing
- A digit is limited to the same two columns in two rows (or the reverse), so it leaves the rest of those lines.
Expert
- Contradiction
- Try another digit in the marked cell and a rule breaks a few steps later. So that digit is out.
Questions
What do a 1 and the largest clue mean?
A 1 means the tallest tower stands next to that clue, hiding everything behind it. A clue equal to the grid size means every tower is visible, so heights rise one by one from that side.
Will I ever have to guess?
No. Every puzzle has exactly one solution that logic alone reaches, at every level.
Is Skyscrapers free to play here?
Yes. Every level is free, with no account and no sign-in.