JPG and JPEG are the same file formats. There is absolutely no difference between a .jpg image and a .jpeg image — both formats apply the identical JPEG compression standard and save pictures in the same way.
The only difference is entirely in the file extension, which is a historical artifact from early computer history. The JPEG format was developed in 1992 by the Joint Photographic Experts Group. When Microsoft introduced Windows in the early era, the system enforced a constraint: extensions had to be no more than 3 characters.
Which forced the 4-character .jpeg extension to be shortened to .jpg for Windows users. Non-Windows systems, which never had the three-character restriction, continued using the complete .jpeg extension from the start.
While both file types function the same in almost every modern software, certain cases where a service may specifically require the .jpeg extension. In these cases, renaming the file from .jpg to .jpeg is all that is needed.
No get more info real conversion of image data is necessary — simply changing the extension resolves the issue usually.
Use alljpgconverters.com for a totally free browser-based JPG to JPEG converter requiring no software necessary.