It supports around 500 image formats and in about 80 formats can be saved using XnView. XnView is also available in a portable format for Windows which you can use without installing at all. If you are intended to use it for commercial purporse then need to buy a license. It is a cross-platform freeware software, free to use only for personal usage. If you want a photo viewer software for Windows 10 which also works on macOS and Linux then XnView should be your choice. XnView: Image Viewer, Photo Resizer & Graphic Converter
