How to solve sliding tile puzzles 3×3 & 4×4
A calm, methodical approach to the classic sliding puzzle. Learn the row-by-row technique used by Thunk players to solve 3×3 Warm-up and 4×4 Classic grids.
The core idea
Sliding tile puzzles look chaotic, but they reward patience over genius. The secret is solving one row at a time and never touching a tile that is already in its final position. Think of it like laying a foundation — once a row is correct, you freeze it and build the next layer on top.
This guide covers the two most popular sizes: the 3×3 (8-puzzle) and the 4×4 (15-puzzle) — the same sizes Thunk calls Warm-up and Classic.
Step 1 — Solve the top row
Place tile 1 in the top-left corner. Then slide tile 2 into the spot next to it.
3×3 example
Tiles 1, 2, and 3 are locked in place (highlighted). The rest of the board is still scrambled. Keep the empty slot below or to the right so you have room to maneuver.
4×4 example
Same idea, one extra tile. Get 1-2-3-4 across the top before moving down. Use the empty cell as a temporary parking spot.
Pro tip
If a tile you need is already in the correct row but in the wrong column, slide it out, bring the correct tile in, then return the displaced tile behind it. It feels like two steps backward, but it locks the row permanently.
Step 2 — Solve the second row
Repeat the exact same logic. On a 3×3, place tiles 4 and 5 left to right. On a 4×4, place 5, 6, 7, and 8.
Treat the top row as a wall — never slide a tile from the top row down into the second row unless you are 100 % sure you can restore it in one move. The safest pattern is to build each row entirely from tiles that are still below it.
4×4 second row locked
Top two rows are now complete. Only the bottom half remains. This is where the puzzle changes character.
Step 3 — Finish the bottom rows
3×3 (Warm-up)
With the top two rows solved, you are left with a simple 2×2 block in the bottom-right. Only tiles 6, 7, and 8 (plus the empty space) can move. Rotate them clockwise or counter-clockwise until they snap into place. If they are in a mirror image, one extra shuffle around the loop fixes it.
Solved 3×3
The empty cell lands in the bottom-right corner. Every tile is in ascending order left-to-right, top-to-bottom.
4×4 (Classic)
On a 4×4, solve the third row next (tiles 9-12). The final two rows then behave like a single 2×4 strip. Cycle tiles through the bottom corners: slide the last needed tile into the bottom-left, then walk it across to its home, using the empty cell as a shuttle. It takes a few more moves than the 3×3, but the logic is identical — small loops, no backtracking, one tile at a time.
Solved 4×4
The full 15-puzzle complete. Rows 1-3 were built left-to-right; the bottom row fell into place as a natural consequence.
Common mistakes to avoid
Solving corners out of order
Always work left-to-right within a row. If you place tile 3 before tile 2, you will have to dismantle the whole row to fix it.
Using the empty cell in the wrong place
Keep the blank spot near the tile you are currently placing. If it drifts to the opposite side of the board, you waste moves herding it back.
Panicking on the last two rows
The bottom of a 4×4 feels cramped because every move ripples. Slow down. Choose one tile, plan two moves ahead, and execute. Speed comes from accuracy, not frantic tapping.
Ready to put this into practice?
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