To preserve transparency in your png, use Erase Mode to erase!
Program Mode:
If you want a black-on-white background for your GIF, fill the canvas with white first! Then remember to erase with white in line mode. Don't use erase mode.
Save your canvas and put in local storage also.
To create a gif, copy images using buttons below, changing the canvas slightly.
Use buttons above to create the frames for your GIF.
Save your images to a file first.
Choose a saved JSON file and then load it. Two steps.