Slider Puzzle
Slide tiles to solve the picture
The Slider Puzzle (also known as the 15 Puzzle or Sliding Tile Puzzle) is a classic spatial reasoning challenge that has fascinated puzzle enthusiasts since the 1870s. Arrange numbered tiles in order by sliding them one at a time into the empty space. The catch: you can't lift tiles — only slide them through the single gap. This constraint transforms a simple ordering task into a rich exercise in sequential planning, where every move affects future possibilities.
How to Play Slider Puzzle
The Grid
A grid of numbered tiles with one empty space. The classic version is 4x4 with tiles numbered 1-15.
Slide Tiles
Move tiles by sliding them into the adjacent empty space. Only tiles next to the gap can move.
Goal: Order Them
Arrange all tiles in numerical order (1-15, left to right, top to bottom) with the empty space in the bottom-right.
One at a Time
Only one tile moves per step. Plan sequences of moves that accomplish your goals without undoing progress.
No Lifting
Tiles can only slide through the empty space. You cannot pick up, swap, or jump tiles.
Count Your Moves
Try to solve in as few moves as possible. The optimal solution requires sophisticated planning.
Strategy & Solving Tips
The Slider Puzzle has well-known solution strategies that break the problem into manageable phases.
- Solve the top row first, then the second row, working downward — completed rows stay intact
- For each row, place the leftmost tiles first, then slide the rightmost tile into position using a rotation technique
- The last two rows must be solved simultaneously as a 2xN puzzle
- Learn the "rotation" technique: cycling 3-4 tiles in a loop to position one without disturbing others
- Corner placements require specific multi-step sequences — practice these patterns until they're automatic
- For minimum-move solutions, think several moves ahead like in chess. The optimal solution for a 4x4 can require 80+ moves
Slider Puzzle FAQ
Is every scramble solvable?
No. Exactly half of all possible tile arrangements are solvable. Our puzzles always start from solvable positions, so you're guaranteed a solution exists.
What's the maximum number of moves needed?
For the classic 4x4 (15-puzzle), the hardest positions require 80 moves to solve optimally. Most random solvable positions need 40-60 optimal moves.
Why is it called the 15 Puzzle?
The classic version has 15 numbered tiles in a 4x4 grid with one empty space. The puzzle was a massive craze in the 1880s, similar to the Rubik's Cube in the 1980s.
How does the puzzle get harder?
Larger grids (5x5, 6x6) increase difficulty exponentially. The number of possible arrangements grows factorially, and the solution length increases significantly.
Ready to Play Slider Puzzle?
Slide your way to the solution in the Slider Puzzle — the timeless spatial challenge where every move counts and planning ahead is everything.