Not sure if here’s the proper category to drop this but I just wanted to share this small tool I’ve created: https://www.dwdeveloper.com/tiled-map-optimizer/
It’s basically I Tiled JSON maps and tileset images optimizer.
If you use Tiled (https://www.mapeditor.org) to create maps for your games, and you are using small parts from multiple big images, then you can use this tool where you can upload a Tiled export JSON file, along with the tilesets images, and you will get a single merged image with only the tiles used, and a new JSON file with all the tiles in layers fixed to use that merged image.
Included a resize feature, ideal for people working in for example 16x16 and want to move to 32x32, or 64x64, just specify the multiplier and that’s it!