15 Puzzle Online Free
Slide the tiles into the empty space until the numbers read in order, 1 to 15, with the gap in the bottom-right corner.
Tap a tile in the same row or column as the gap to slide it. Arrow keys work too. Tiles in the right place light up.
What is the 15 puzzle?
The 15 puzzle is the best-known sliding tile puzzle: fifteen numbered tiles sit in a 4 × 4 frame with one empty space, and you slide tiles into the gap until they read 1 to 15 in order. The 3 × 3 version is called the 8 puzzle and the 5 × 5 version the 24 puzzle.
It became a worldwide craze in 1880. Exactly half of all possible tile arrangements can’t be solved, which mathematicians proved with a neat parity argument, so every shuffle here is checked to be one of the solvable half. For more number puzzles, try the 24 Game or Magic Square.
How to play 15 Puzzle
- Tap any tile in the same row or column as the empty space and it slides towards the gap, pushing any tiles in between.
- On a keyboard, the arrow keys slide the tile next to the gap into it.
- Arrange the tiles in order from left to right and top to bottom, with the gap in the bottom-right corner.
- Your moves and time are counted. Hint slides one tile along a good route, Undo takes a move back and Clear goes back to the starting shuffle.
15 Puzzle skills
- Planning ahead
- Number order
- Problem solving
Level: Ages 7 and up
Tips for the 15 puzzle
Solve the top row first, then the left column, and you’re left with a smaller puzzle. Repeat until only a 2 × 2 corner is left.
Place the last two tiles of a row together: put the final tile below its spot, the one before it in the corner, then rotate both in.
Don’t disturb finished rows. Plan routes for the gap that stay in the unsolved part of the board.
The 3 × 3 puzzle is great for learning the moves: any shuffle can be solved in 31 moves or fewer.
15 Puzzle questions and answers
Can every 15 puzzle be solved?
No. Exactly half of all arrangements are impossible. Every puzzle here is generated to be solvable, so a solution always exists.
What is the fewest moves to solve the 15 puzzle?
Any solvable 15 puzzle can be finished in 80 moves or fewer, and the 8 puzzle (3 × 3) in 31 or fewer. A typical human solve takes a lot more, which is fine.
What is a sliding number puzzle?
A sliding number puzzle, or sliding tile puzzle, is a frame of numbered tiles with one empty space. You slide tiles into the gap to put the numbers in order. The 15 puzzle is the most famous one, and you can play all three sizes online here.
Is the 15 puzzle free to play online?
Yes. This 15 puzzle is free online with no sign-up or download, on phones, tablets and computers. Each New gives a fresh shuffle that is guaranteed to be solvable.
What is the 8 puzzle?
The 8 puzzle is the 3 × 3 version, with tiles 1 to 8. It’s the best place to start. The 24 puzzle is the 5 × 5 version.
Who invented the 15 puzzle?
It was made by Noyes Chapman, a postmaster in New York, in the 1870s, and it swept the world in 1880.