Yes, JPG and JPEG are the same thing. They are two spellings of one image format, not two different formats. A file named photo.jpg and a file named photo.jpeg can hold the identical picture with the identical quality. If that is all you came for, you are done. But it is worth understanding why there are two names, because the confusion comes up constantly.
Where the two spellings came from
JPEG stands for Joint Photographic Experts Group, the committee that designed the format and released it in 1992. So JPEG is the real name, and the file extension was originally .jpeg to match.
The problem was early Windows and DOS. Those systems used a filing rule called 8.3, which allowed file extensions of only three characters. Four letters was one too many, so ".jpeg" got trimmed to ".jpg" on those computers. Mac and Linux never had that limit and happily used ".jpeg."
That split stuck around. Today the three-character limit is long gone, but both extensions survived out of habit. Windows tends to favor .jpg, a lot of cameras and Apple devices lean toward .jpeg or .jpg depending on the model, and the internet is full of both. Same format, two labels.
Is one higher quality than the other?
No. This is the question that brings most people here, so to be clear: there is no quality difference between JPG and JPEG. Neither compresses more, neither looks sharper, neither preserves more detail. They are the same format, so a .jpg and a .jpeg saved with the same settings are byte-for-byte identical.
Image quality in a JPEG comes from the compression level chosen when the file is saved, not from the extension on the end. A heavily compressed .jpeg will look worse than a lightly compressed .jpg, but that is about the settings, not the spelling. Swap the extensions and nothing changes.
You can prove this to yourself. Take any photo, make a copy, and change one copy's extension from .jpeg to .jpg. Check the file size of both: it will be exactly the same, down to the byte. Open them side by side and they are indistinguishable, because they are literally the same file with a different name on the label.
Does renaming .jpeg to .jpg do anything?
Renaming a file from .jpeg to .jpg changes nothing about the image. The pixels, the colors, the compression, the file size, all of it stays exactly the same. You are only relabeling the file, not re-encoding it. It opens and displays identically before and after.
This matters because people sometimes assume renaming will "convert" or degrade the file. It does neither. The bytes inside the file are untouched.
When you might still want to standardize the extension
If they are the same, why does a converter for this even exist? Because some software is fussy about the label even though the content is identical.
You will run into this with certain upload forms, job application portals, government websites, and older apps that check the file extension and only accept ".jpg." Feed them a ".jpeg" and they reject it, not because anything is wrong with the image, but because their rule was written to look for three letters. Batch processes and scripts sometimes have the same rigid expectation.
In those cases you want every file to end in .jpg, consistently. You could rename them one by one, but that is tedious for a folder full of images, and on phones or locked-down work computers you may not have an easy way to rename at all. The JPEG to JPG converter standardizes the extension for you in the browser, so a form that insists on .jpg will accept your files. It is the fastest fix when the picture is fine and only the label is the problem.
The bottom line
JPG and JPEG are the same image format with two names, born from an old three-character file limit that no longer exists. There is no quality difference, and renaming one to the other changes nothing about the image. The only reason to standardize on .jpg is to satisfy software that is picky about the extension.
If you want to understand the format itself, how it compresses images and where it fits among other file types, read our guide on what a JPG file actually is.