About Sliding Puzzle
The sliding puzzle, also known as the 15 puzzle or the number slide puzzle, is one of the oldest brain teasers in the world. It used to come as a little plastic box full of tiles that slide around. The board holds mixed-up numbers and one empty space, and the only thing you can do is slide a tile next to the gap into it.
Your job is to put the numbers in order from 1 to the end: the top row from left to right, then the next row, with the empty space finishing in the bottom right corner. Every tile that sits in its correct place lights up green, so you can see you're on the right track.
There are two levels: Easy is a 3x3 board with 8 numbers for beginners and younger players, and Hard is a 4x4 board with 15 numbers for anyone who wants a bigger challenge. Every puzzle can always be solved, and the game counts your moves and time and saves your fewest moves for each level. It builds planning, patience and step-by-step thinking.
How to play
- Choose a level: Easy (3x3) or Hard (4x4).
- Click or tap a tile next to the empty space to slide it in.
- You can also tap a tile further along the same row or column, and all the tiles between it and the gap slide together.
- Put the numbers 1, 2, 3... in order from left to right and top to bottom.
- Try to finish in as few moves as possible to beat your record.
Controls
| Keyboard | Arrow keys or W A S D: the Left arrow slides the tile to the right of the empty space to the left into it, and so on. |
|---|---|
| Mouse | Click any tile in the same row or column as the empty space to slide it. |
| Touch | Tap a tile to slide it into the empty space. |
Tips to win
- Solve the top row first, then leave it alone and move on to the next row.
- Place the last two numbers of a row together: line them up just below their spots, then slide them in at once.
- If you get muddled, stay calm: the green tiles are already in the right place.
Sliding Puzzle: questions and answers
Can the sliding puzzle always be solved?
Yes. The game mixes the tiles up using real moves from the finished order, so every puzzle definitely has a solution.
What's the difference between the 8 puzzle and the 15 puzzle?
The 8 puzzle is the 3x3 board with 8 numbers, which is the easy level. The 15 puzzle is the 4x4 board with 15 numbers, which is the hard level.
What age is the number slide puzzle for?
It suits everyone from about age 6 up: the easy level is a gentle start, and the hard level is a real challenge for adults too. It's great for logical thinking and planning.
How do I solve a sliding puzzle quickly?
Solve it one row at a time from the top, and on the big board finish the last two rows one column at a time. With practice you'll need fewer and fewer moves.