You can use animated GIFs as your main product image without any issues.
When you upload a new product or a category image, Ecwid creates a new thumbnail on its basis. If the "main" product image is bigger than your thumbnails, it will be resized. If it is smaller, it will be saved unchanged.
When you upload a GIF image, Ecwid creates its thumbnail in JPEG format. JPEG files don't support animation, so thumbnails don't have it either.
So in order to use animated GIFs for your product and category thumbnails, your product images which you upload should have the same size as your thumbnails.
- Log in to your UXi® Commerce control panel and open the "System Settings → Design → Thumbnail Sizes" page.
- Increase your thumbnails` size to 240px, for example.
- Then try to upload your animated GIF which should be equal to or less than 240px and check the thumbnail.