JPG vs. JPEG: Is There a Difference?

Updated December 9, 2022

When creating a website, adjusting a media post or preparing a memo, understanding the significance of image files can improve your overall work quality. JPG and JPEG image files are similar file formats that are among the most popular file formats used by businesses and departments that use media.

In this article, we compare JPG and JPEG file formats and explore the details of both image file formats.

JPG vs. JPEG

JPG and JPEG are two equivalent file extensions that both refer to the same digital image format, so there are actually no differences between the JPG and JPEG formats. The only difference is the number of characters used. JPG files are saved with the file extension .jpg, and JPEG files are saved with the file extension .jpeg.

The term JPEG is an acronym for the Joint Photographic Experts Group, which is the name of the International Organization for Standardization (ISO) subcommittee that helped create the standard in 1992.
JPG exists because the earlier versions of Windows operating systems had a maximum 3-letter limit when it came to file names. UNIX-like operating systems like Mac or Linux never had this limit.

Nowadays, newer versions of Windows now accept file extensions that have more characters and most apps understand and open both JPG and JPEG files equally. If you have files with either extension that your image viewer or editor can open without issues, there’s no need to convert JPGs to JPEGs or vice versa.

Tip: The JPEG and JPG file formats are generally interchangeable on most modern operating systems.

Some more similarities between JPG and JPEG file formats include:

Raster imaging

Both JPG and JPEG image formats use the pixel processing program raster imaging. This process uses pixels as individual points to create an image. Because they use raster imaging, both JPGs and JPEGs are optimal for nonlined, subtly-hued images such as logos, intricate art and high-density photos. Due to their pixel-based imaging system, both file types show lower quality if a user enlarges the photo too much.

Image quality loss

Because both JPGs and JPEGs use pixel-based imaging programs, the files eventually lose quality over time with each transfer. Every time a user saves an image, the pixel transfer from the source location to storage shrinks, meaning that each pixel shrinks as well. While this image quality loss is relatively unnoticeable, this shared quality is why both image file types are best viewed within their original source location, rather than as a saved image.

Related: 10 Types of Image File Formats

What is JPEG?

A JPEG is an image format and file extension that is used in a wide variety of internet mediums, such as blog posts, company websites and social media posts. JPEGs are modern image formats that allow for convenient internet usage and have a variety of features to make them optimal for posting and high-speed uploads and downloads. The term JPEG stands for three different things:

1. JPEG lossy compression

JPEG is a lossy compression method used to ensure the digital images being used are as small as possible and load quickly when someone wants to view them. Data compression is the act or process of reducing the size of a computer file. Images saved in the JPEG file format take up 50-75% less disk space, reducing the time needed to load, transfer or download them. There are two types of data compression:

Lossy compression involves permanently removing unnecessary metadata from the image file to compress it. This format is suitable for file types in which lost details are hardly perceptible.
Lossless compression refers to compression in which the image is reduced without any quality loss. GIF, PNG, RAW and BMP are all lossless image formats.

Digital cameras compress raw photographs as JPEG images to make the files smaller in size. JPEG typically achieves compression ratios ranging from 10:1 to 20:1, with little perceptible loss in image quality. It’s important to note that the more editing and saving of a single JPEG image you do, the worse the quality of the image will be. That’s why it’s best to work with the original JPEG image, determine your edits, and then save the final version without re-saving it multiple times.

Tip: JPEG lossy compression is usually used for photographs and complex still images.

2. The Joint Photographic Experts Group

The Joint Photographic Experts Group is the tech industry group that created the JPEG image format. The group is a subcommittee of the ISO, which is an independent, nongovernmental international organization based in Geneva, Switzerland. The ISO has a membership of 167 national standards bodies, which work together to develop consensus-based international standards that cover many aspects of technology, management and manufacturing.

3. The JPEG file format

The last way the term JPEG is used is when referencing a way to store and save digital images. JPEG is a type of file format that can convert into many other image file types, including JPG.

Because of their modern construction, JPEGs can also retain visibility and pixel density no matter what size or file type users convert them to. Data reduction, or the deterioration of data during multiple transfers over time, is a minimal issue concerning JPEGs.

Tip: JPEG is the most common image file format used by digital cameras and other image-capturing devices.

What is JPG?

The JPG file format is the same as the JPEG file format, with fewer characters in its file extension, .jpg. Earlier versions of the Windows operating systems MS-DOS 8.3 and FAT-16 had a maximum three-letter when it came to file extensions, so JPEG images had to be saved using the .jpg file extension so they didn’t exceed the 3-letter limit.

Although JPGs are no longer the standard for file clarity and size, they're versatile in use across multiple sites and systems. Some photo editing programs like Adobe Photoshop and Gimp save JPEGs by default to the .jpg extension on both Windows and Macs.

Please note that none of the companies mentioned in this article are affiliated with Indeed.