Number Slide

Four by four, one gap. Slide the tiles back into order.

Controls — Tap a tile next to the gap, or use the arrow keys.

How to play

1. One square is empty. Tap a tile beside the gap to slide it in.
2. Put 1 in the top left and work along the top row, then the left column.
3. Order 1–15 with the gap last. Every shuffle here is guaranteed solvable.

Tips

• Solve the top row and left column first, then never move them again.
• To place the last two tiles of a row, park them in the row below and rotate them in together.
• Half of all arrangements cannot be reached from the solved board — that is why this one shuffles by walking, not by scattering.

About this game

Number Slide is the 15-puzzle, the oldest sliding-tile puzzle there is. Its famous trick is that half of the possible arrangements are unreachable: an odd number of swaps and the board can never be solved.

The shuffle here makes that impossible by construction, so a dead board never happens. The undo button exists because a wrong move is usually recoverable in two taps.

No download, no account, no tracking, no ads.

FAQ