JPEG and JPG are the same photo formats. There is absolutely no distinction between a .jpg file and a .jpeg image — both use the identical JPEG compression algorithm and store photos in the exact same format.
The difference is entirely in the suffix, as it is a historical artifact from early computer history. JPEG was introduced in 1992 by the Joint Photographic Experts Group. When Microsoft introduced Windows in the early era, the OS imposed a constraint: extensions had to be no more than 3 characters.
This forced the four-character .jpeg extension to be shortened to .jpg for Windows users. Apple and Unix platforms, without this character limit, used the complete .jpeg extension from the here beginning.
While both extensions work identically in virtually all modern software, certain scenarios when a system might need the .jpeg extension. In these cases, changing the extension from .jpg to .jpeg is all that is needed.
No image file conversion is needed — just renaming the extension fixes the problem in most cases.
Use alljpgconverters.com offering a completely free web-based JPG to JPEG tool without software necessary.