Slide Puzzle

The classic sliding-tile puzzle: push numbered tiles through one gap back into order, on a 3×3 or 4×4 board, against the clock.

Slide Puzzle

The classic sliding-tile puzzle. Numbered tiles sit in a tray with a single empty gap. Slide them through the gap until they read 1, 2, 3… row by row with the gap in the bottom-right corner — as fast as you can.

How to play

1. Pick a difficulty and press Shuffle and start.
2. Tap a tile in the same row or column as the gap. It slides toward the gap, and so does every tile

between it and the gap.

1. Keep sliding until every tile is home. The clock stops the moment the last tile lands.

Every tile that moves counts as one move, so sliding a row of three tiles at once is three moves.

Every board is equally hard

Each board is shuffled from its own random seed, is always solvable, and has its shortest possible solution computed exactly (optimal IDA* search) before you see it. That shortest solution always falls inside a fixed range for the difficulty, so every board on a leaderboard asks the same amount of work:

Normal, Hard

Board, 3×3, 4×4

Tiles, 8, 15

Shortest solution of every board, 22–26 moves, 44–48 moves

Solving by hand, usually 30–80 moves, usually 100–250 moves

Achievement, —, Fifteen, Hard only

On Normal the board is drawn uniformly at random from every 3×3 position whose shortest solution is 22–26 moves. On Hard the board is scrambled from the solved tray, and only scrambles whose proven shortest solution is 44–48 moves are kept.

Score

• Your score is the time to solve the board, to a tenth of a second. Lower is better.
• Normal and Hard have separate leaderboards.
• The result screen shows your moves next to the proven shortest solution, the extra moves you took,

and the puzzle code (such as #3FA9-C21B) of the board you solved.

• The clock stops while the game is paused, and the board is hidden so nobody can plan ahead.

Controls

Action, Mouse and touch, Keyboard

Slide a tile or a row of tiles, Tap a tile in line with the gap, —

Move the tile beside the gap, Swipe in the direction it should move, Arrow keys or WASD

Pause, Pause button, Esc or P

Arrow keys move a tile in the direction of the arrow: ← moves the tile to the right of the gap leftwards into the gap. Swiping a tile toward the gap slides its whole row segment at once.

Picture mode

Switch the tiles from Numbers to Picture to play with an abstract picture painted for that puzzle from its seed. Every tile keeps a small number, so the puzzle never becomes guesswork.

The game pauses when its window loses focus. Sound, reduced motion and the interface language (English, Korean, Japanese, Chinese) can be changed at the top of the game.

Tip

Finish the top row first, then the left column. What is left is a smaller puzzle of the same kind.