JPG and JPEG are the same file formats. There is absolutely no difference between a .jpg image and a .jpeg file — they both employ the very same JPEG encoding method and save photos in the same way.
The difference is only in the suffix, being a historical artifact from early computing. JPEG was introduced in 1992 by the Joint Photographic Experts Group. Early Windows introduced early versions of Windows, the OS had a constraint: extensions could only be no more than 3 characters.
Causing the four-character .jpeg suffix to be abbreviated to .jpg for Windows users. Non-Windows systems, without this extension limitation, could use the longer .jpeg extension from the outset.
Although both extensions function the same in virtually all today's programs, there are more info specific scenarios where a service might need the .jpeg file type. In these cases, converting from .jpg to .jpeg is all that is needed.
No image conversion of image data is necessary — simply changing the extension solves the compatibility concern in most cases.
Try alljpgconverters.com offering a totally free browser-based JPG to JPEG tool requiring no software needed.