How to Solve a Sliding Puzzle Step by Step
A sliding puzzle (also called a 15 puzzle or tile puzzle) looks random, but one simple routine solves every board from 3×3 to 8×8. The idea: lock in the top row, then the next, and never touch finished rows again.
1. Solve the top row, tile by tile
Bring tile 1 to the top-left corner. Then bring tile 2 next to it, then 3. Move the empty space around a tile to push it where you want: to move a tile left, put the empty space on its left and slide it in.
2. The last two tiles of a row
The last two tiles of a row cannot simply be placed one after the other without breaking the row. Instead, put the last tile (say 4) in the spot where 3 belongs, then bring tile 3 directly below it. Now move the empty space into the corner where 4 belongs, slide 4 right, then slide 3 up. Both drop into place together.
3. Repeat row by row until two rows are left
Treat the board under the finished rows as a smaller puzzle. A 5×5 with one row finished is now a 4×5, and so on.
4. Finish the last two rows column by column
For the last two rows, work left to right in pairs: the top tile and bottom tile of each column. Use the same trick turned sideways: put the bottom tile in the spot where the top tile belongs, bring the top tile right next to it, move the empty space into the bottom spot, then slide the bottom tile down and the top tile left.
5. The final 2×2
The last three tiles just rotate around the empty space. Keep circling in one direction until they line up.
Tips
- Look at the picture, not only numbers. Turning numbers off on small boards makes it feel like a real jigsaw.
- Slide whole rows at once to save moves.
- If you are lost, peek at the finished picture or ask for a hint.
In Tesslide you can practice this on any photo, from a quick 3×3 to a long 8×8, and your puzzle saves after every move.
FAQ
How many moves does a 4×4 take?
Beginners often need 150 to 300 moves with this method. Speed comes from practice, not from a different method.
Is the method the same for 6×6 or 8×8?
Yes. Solve rows from the top until two rows remain, then solve those two rows column by column. Bigger boards just repeat the same steps.
What if I mess up a finished row?
Use undo, or simply re-solve that row. Never break a finished row on purpose except during the last-two-tiles trick, where you restore it right after.