How do you play the Sliding Puzzle?
Slide tiles into the empty space until the numbers run in order from 1 at the top left to the last one at the bottom right. The 4×4 version has 15 tiles, which is why it is called the 15 puzzle.
A tile can only move into the gap when it sits right next to it. The puzzle is solved when the gap ends up in the bottom right corner. Every shuffle is guaranteed to be solvable.
How do the tiles move?
- One step: only a tile touching the gap can slide into it, never diagonally.
- Whole lines: tap any tile in the same row or column as the gap and every tile between them slides over at once.
- Move count: each tile that moves counts as one. Sliding three tiles in a line counts as three.
- Timer: starts with your first move.
- Picture mode: a clay picture is cut into tiles instead of numbers. Turn on numbers to see small labels in the corners, or tap Peek to see the finished picture for a moment.
What changes with the board size?
| Board | Tiles | What to expect |
|---|---|---|
| 3×3 | 8 | Great for a first try. The shortest solution is never longer than 31 moves. |
| 4×4 | 15 | The classic 15 puzzle. Computer searches proved every position can be solved in 80 moves or fewer. |
| 5×5 | 24 | A good step up once you know the method. |
| 6×6 | 35 | The biggest board and a real marathon. |
Tips for solving faster
- Finish the top row first. Once it is done, leave it alone and treat the rest as a smaller puzzle.
- Place the last two tiles of a row together. On 4×4, park 4 where 3 belongs with 3 right below it, then rotate both in.
- After two rows, solve the left column. The final 2×2 corner falls into place by cycling the gap around it.
- Slide whole lines. Moving several tiles in one tap saves time.
What is the daily puzzle?
Every day everyone gets the same shuffled 4×4 number board, and it changes at midnight Korea time. Since the board is identical, you can compare moves and time with friends.
Your fewest moves and fastest time for each board size are saved in this browser. Friends who open your shared link get the exact same shuffle to beat.