Combine local sprites into a PNG atlas and download exact frame coordinates as JSON.
Your input
Outputs are cleared when the input changes.
Result
Enter your data or use the example, then run the tool.
Worked example
Two 16 × 16 sprites with maximum width 32 and spacing 0 produce a 32 × 16 atlas, with frames at (0, 0) and (16, 0).
Method
A deterministic shelf packer uses input order and starts a new row when the next sprite cannot fit. JSON records each stable ID, source filename and exact source-sized rectangle.
Limits
Not optimal bin packing. Images are not rotated, resized or trimmed. Maximum 100 files, 20 MiB each, 100 MiB total input and 40 million decoded pixels. Output is at most 40 million pixels and 16384 pixels on either side.
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