Tile Puzzle Solver

Tile describes a piece, not a movement rule

A tile puzzle can be a sliding board, a matching game, a mosaic, an edge-fitting puzzle, or a rotation challenge. The word tells you that the game uses separate pieces, but it does not tell you which moves are allowed. The tool on this page is for the sliding branch: square tiles remain in a frame, one cell is empty, and neighboring pieces slide into that blank.

This page opens the sliding puzzle solver with a 3x3 numbered example. It also supports picture pieces and square boards up to 8x8. If your game removes matching tiles, rotates them in place, swaps arbitrary neighbors during play, or contains fixed obstacles, it needs a different solver. Representing those mechanics as ordinary slides could produce an answer that the game will not let you execute.

Give every piece a stable identity

Numbered tiles already have convenient identities. In the usual goal, tile one belongs in the top-left cell, with later numbers continuing across the rows. A picture puzzle needs identities too, even when the crops contain no printed labels. Upload the completed image and assign numbers by the crops' finished locations, left to right and top to bottom. Two patches of similar color are still different pieces if they occupy different goal cells.

The blank is a cell, not an additional numbered tile. Enter it as 0 or _. Do not reuse a label for two pieces because they look interchangeable. The editor expects each number exactly once, so a full board can be mapped consistently to the target and replayed without ambiguity.

Record positions separately from the goal

Choose the board size, then use Edit start to arrange the current cells. Clicking two cells exchanges them in the editor. For number entry, open Type numbers, type the entire board in row order, and separate entries with spaces or commas. Include the blank at its exact position. Input validation reports a count mismatch, a repeated label, or an invalid value.

If your target uses an unusual order, set it with More → Edit goal. A board can be reachable from one target and unreachable from another even though all labels are present. A tile puzzle showing the blank at the top-left is therefore not automatically represented by the default bottom-right-blank finish. Establish the target before treating a solvability result as a verdict on your game.

A local match can obstruct a global route

Sliding tiles interact through the blank. Putting a tile in its destination too early can block the corridor needed for a neighbor. Common examples include a row whose last pair is reversed, a first column completed before its bottom pair is organized, or a picture frame assembled while the interior still needs access to an edge.

These situations differ from free-placement mosaics, where a correct piece can usually stay untouched. In a sliding board, a piece may have to leave its destination temporarily so the blank can circulate. The replay shows those detours explicitly. Judge progress by the route as a whole rather than expecting every move to increase the number of correct tiles.

What the order check can establish

The tool verifies both a complete input and the relationship between start and goal. The reachability check uses tile-order parity together with the blank position. On odd-width boards the standard goal has an even numbered-tile inversion count; on even-width boards the blank row also participates in the condition. A simple visual resemblance to the target cannot replace this check.

An impossible arrangement produces a visible explanation and a repair option. Fix it exchanges a neighboring numbered pair and changes the board into a reachable one. When copying a puzzle you cannot physically modify, check for mistaken labels or a wrong goal instead of assuming that the repaired board is the original task.

From a validated board to replay

Press Solve once the identities and positions are right. Small and large boards use different search strategies. A 3x3 board uses a goal-based distance table; 4x4 supports heuristic search with pattern databases; boards from 5x5 upward construct a route by placing rows and columns and protecting completed cells. The larger-board method provides a fast answer without exhaustively comparing every complete route.

Each displayed move slides one named tile into the blank. Its arrow indicates the tile's direction, and the move count uses single-tile slides. Pause, step backward or forward, adjust playback speed, or click a step to inspect an awkward cycle. For a photo, keep numbers visible while following the route so similar textures do not cause a mistaken move. The pages below separate sizes and puzzle types, making it easier to find guidance for your exact board mechanics.