Hello, 

using brave browser on mac os, I have not been able to get image upload to work. The upload form doesnt seem to be working for me. Dragging and dropping diplays the image, but posting fails claiming the length is too long. I have tried exporting the image as a small png, or webp image without success. 

Any suggestions on recommended file formats or sizes for images?

Good morning - the webp image format is not currently supported on the website but that may change soon. Dragging and dropping will also not work on that particular page. You have to use the "Select Image" button to choose the file to upload. It looks like you did manage to get your image uploaded once it was converted to a .jpg?