Is JPEG better quality than JPG?

No, they're the same format; quality depends on the compression setting, not the extension.

Why does a website reject my .jpeg file?

Some forms only list .jpg. Rename the file or convert it.

JPG vs JPEG: Is There a Difference?

There's no difference: JPG and JPEG are two file extensions for exactly the same image format. The only reason both exist is an old Windows limit on file extensions.

JPG vs JPEG

They're identical. .jpg and .jpeg files contain the same JPEG image data, and you can rename one to the other safely.

JPG vs JPEG at a glance

Property	JPG	JPEG
Image data	JPEG (ISO/IEC 10918)	JPEG (ISO/IEC 10918)
Extension length	3 letters	4 letters

Use JPG for

Windows and most cameras default to .jpg
Any upload form or app

Use JPEG for

macOS and some apps use .jpeg
Exactly the same uses as .jpg

Key differences

Why two extensions?

Early Windows (MS-DOS) only allowed three-letter extensions, so JPEG became .jpg. Mac and Unix allowed .jpeg, and both stuck.

Quality and size

Identical. The extension doesn't change the image data at all.

What about .jfif?

JFIF is also a JPEG image with another extension. Some sites reject .jfif, so converting it to .jpg is handy.

JPG

What is a JPG file?

JPG is functionally identical to the JPEG format, differing only in the file extension length, a legacy constraint from the MS-DOS 8.3 filename limit (which allowed only three characters for extensions). It implements the same ISO/IEC 10918 standard, using lossy compression based on Discrete Cosine Transform (DCT) and Huffman coding to store photorealistic images. The file structure contains markers such as Start of Image (SOI) and End of Image (EOI) and supports color spaces like sRGB and CMYK, making it interchangeable with .jpeg files in all software contexts.

How to open a JPG file

As one of the most ubiquitous file types in computing, JPG files open natively on Windows, macOS, and Linux without external software. Default viewers like Microsoft Photos, Apple Preview, and Linux image viewers handle the format automatically. For editing or conversion, industry-standard tools including Adobe Photoshop, Paint.NET, and XnView provide extensive support. Web browsers universally render JPGs without plugins.

Full Name: Joint Photographic Experts Group
Developed By: Joint Photographic Experts Group
Initial Release: 1992
MIME Type: image/jpeg