Make a PNG sprite sheet and JSON map

Arrange two through sixty-four supported raster images in fixed cells and download one PNG plus a top-left-origin JSON coordinate map in a ZIP.

When this tool is useful

Packaging small game sprites, icons, thumbnails, or UI states into one predictable bitmap with machine-readable cell coordinates.

How local processing works

Inputs stay in selected order, columns are bounded by the actual input count, every frame receives a fixed cell, contain centers the full image and cover fills then crops, gaps keep the chosen RGBA background, and the ZIP contains sprite-sheet.png plus deterministic sprite-sheet.json coordinates.

How to use it

  1. Prepare a safe working copy: Keep every source unchanged and review the supported input, controls, and limits before processing. Packaging small game sprites, icons, thumbnails, or UI states into one predictable bitmap with machine-readable cell coordinates.
  2. Process locally: Run the documented operation in this browser and stop if an unsupported structure is reported. Inputs stay in selected order, columns are bounded by the actual input count, every frame receives a fixed cell, contain centers the full image and cover fills then crops, gaps keep the chosen RGBA background, and the ZIP contains sprite-sheet.png plus deterministic sprite-sheet.json coordinates.
  3. Download and verify: Extract both files, confirm PNG dimensions, top-left origin, frame order and cell rectangles against the JSON, inspect contain padding or cover crops, and load the map in the consuming application.

Important limitations

The PNG is one flattened raster sheet: animation, vectors, layers, source metadata, independent containers, and color-profile intent are not retained. Cover can crop edges, contain can leave background, and source, total-pixel, canvas, memory, PNG, JSON, and ZIP limits apply.

Verify the downloaded result

Extract both files, confirm PNG dimensions, top-left origin, frame order and cell rectangles against the JSON, inspect contain padding or cover crops, and load the map in the consuming application.

Private by design

Your files stay in this browser. The tool does not upload the source or output to our servers.

Questions and answers

When is this tool useful?

Packaging small game sprites, icons, thumbnails, or UI states into one predictable bitmap with machine-readable cell coordinates.

What does the browser actually do?

Inputs stay in selected order, columns are bounded by the actual input count, every frame receives a fixed cell, contain centers the full image and cover fills then crops, gaps keep the chosen RGBA background, and the ZIP contains sprite-sheet.png plus deterministic sprite-sheet.json coordinates.

Which limits must I understand?

The PNG is one flattened raster sheet: animation, vectors, layers, source metadata, independent containers, and color-profile intent are not retained. Cover can crop edges, contain can leave background, and source, total-pixel, canvas, memory, PNG, JSON, and ZIP limits apply.

How should I verify the result?

Extract both files, confirm PNG dimensions, top-left origin, frame order and cell rectangles against the JSON, inspect contain padding or cover crops, and load the map in the consuming application.

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