Do I need an account?

No. Opening the page is the whole setup.

Is every shuffle really solvable?

Yes. The board is shuffled by sliding tiles from the solved position, so reversing those slides always works.

Where is my record kept?

In this browser on this device, separately for each board size. The one exception is pressing Submit on today's board, which sends your name and your sequence of moves so the ranking can list it. Nothing leaves unless you press it.

What is sent to the ranking?

The sequence of moves you played, not a score. The move count is recomputed on the other end by replaying that sequence. Accepting a score directly would let anyone submit any number they liked. No files are sent.

Does it work on a phone?

Yes. Press a tile and it slides.

Does it work offline?

Yes. Once the page has loaded, it plays through with the network off.

What if I stop halfway?

The board and the move count are kept, and reopening resumes from there.

Fix the top row first

Complete the top row left to right, then the leftmost column. Once a row or column is done, leave it alone and work inside the smaller square that remains. On a 4x4, finishing one row and one column turns the rest into a 3x3 problem. Trying to move everything at once undoes work you have already finished.

When the last two will not fit

The two tiles at the end of a row cannot be placed in order directly. Put the last tile one square below its destination, place the other to its left, then rotate the pair into place together. The shape is identical every time, so learning it once covers 4x4 and 5x5 alike.

Why half of them are impossible

Each slide changes the number of inversions in the sequence together with the gap position, in a fixed relationship. Legal moves cannot break that relationship, so any arrangement whose relationship differs from the solved board is unreachable. A random arrangement lands on the wrong side half the time — which is the whole reason this puzzle shuffles from the solved board instead.

How moves are recorded

The fewest moves is kept separately for each board size. Moves count tiles that moved, so sliding three at once costs the same as three single slides. The known worst cases are 31 moves for 3x3 and 80 for 4x4.

Back to all tools／ Games

Sliding puzzle

Runs in your browserNothing is uploaded

Slide numbered tiles into the single empty square until they run in order. Every shuffle here can be solved. Choose 3x3, 4x4 or 5x5; the fewest moves is what gets recorded.

Moves

Fewest

—

Placed

15/15

Today's ranking

Nobody has submitted yet

What gets sent is the sequence of moves, not a score — the move count is recomputed on the other end. No files are sent.

Mode

Today's board is the same for everyone, and always 4x4.

Press a tile in the same row or column as the gap and it slides, along with everything between. Put them in order to finish.

Keyboard: arrow keys slide a tile in the direction you press

Press a tile in the gap row or column and everything between slides. Moves count the tiles that moved.

All tools

Why this one

No unsolvable boards: Scatter fifteen tiles at random and exactly half of the results can never be put in order. Nothing on screen distinguishes the two cases, so a player can fight an impossible board indefinitely. This one shuffles by actually sliding tiles from the solved position, so reversing those slides always gets you back.
Whole rows slide: Press a tile sharing a row or column with the gap and every tile between them moves. Carrying a tile across the board takes one press instead of several. Moves count the tiles that moved, so sliding several at once is faster but never cheaper.
Placed tiles are marked: A tile sitting in its final position is tinted, and the count of placed tiles is shown above the board. Progress is visible at a glance, which makes it easy to come back to a board you left half-finished.

How to play

Pick a size
3x3, 4x4 or 5x5. Choosing a size shuffles a fresh board straight away.
Press a tile
Any tile in the gap row or column slides. The arrow keys work too.
Put them in order
Tiles run 1, 2, 3 … from the top left, with the gap ending at the bottom right.

Solving it

Fix the top row first: Complete the top row left to right, then the leftmost column. Once a row or column is done, leave it alone and work inside the smaller square that remains. On a 4x4, finishing one row and one column turns the rest into a 3x3 problem. Trying to move everything at once undoes work you have already finished.
When the last two will not fit: The two tiles at the end of a row cannot be placed in order directly. Put the last tile one square below its destination, place the other to its left, then rotate the pair into place together. The shape is identical every time, so learning it once covers 4x4 and 5x5 alike.
Why half of them are impossible: Each slide changes the number of inversions in the sequence together with the gap position, in a fixed relationship. Legal moves cannot break that relationship, so any arrangement whose relationship differs from the solved board is unreachable. A random arrangement lands on the wrong side half the time — which is the whole reason this puzzle shuffles from the solved board instead.
How moves are recorded: The fewest moves is kept separately for each board size. Moves count tiles that moved, so sliding three at once costs the same as three single slides. The known worst cases are 31 moves for 3x3 and 80 for 4x4.

Questions

Do I need an account?: No. Opening the page is the whole setup.
Is every shuffle really solvable?: Yes. The board is shuffled by sliding tiles from the solved position, so reversing those slides always works.
Where is my record kept?: In this browser on this device, separately for each board size. The one exception is pressing Submit on today's board, which sends your name and your sequence of moves so the ranking can list it. Nothing leaves unless you press it.
What is sent to the ranking?: The sequence of moves you played, not a score. The move count is recomputed on the other end by replaying that sequence. Accepting a score directly would let anyone submit any number they liked. No files are sent.
Does it work on a phone?: Yes. Press a tile and it slides.
Does it work offline?: Yes. Once the page has loaded, it plays through with the network off.
What if I stop halfway?: The board and the move count are kept, and reopening resumes from there.

Related tools

Why this one

How to play

Pick a size

Press a tile

Put them in order

Solving it

Questions