JPG vs JPEG: what's the difference?

None in the picture: .jpg and .jpeg are two endings for the same JPEG format. The shorter one dates from the three-letter file extensions of MS-DOS and early Windows.

JPG and JPEG are the same thing. JPEG is the image format, named after the Joint Photographic Experts Group that created it, and its files end in either .jpg or .jpeg. The ending is only part of the file's name: it doesn't change a single byte of the picture, its quality or its size. Apps open both, and the official registration of the JPEG media type lists both endings.

Why there are two endings

The JPEG standard was published in 1992. At the time, MS-DOS and Windows limited file names to eight characters plus an extension of at most three, the "8.3" rule, so the four-letter .jpeg became .jpg. Windows 95 brought long file names, but by then .jpg was the habit. Systems without the old limit could use .jpeg all along, which is why both endings are still in use.

Other endings for the same format

Besides .jpg and .jpeg, you may see .jpe, .jfif and .jif. All of them hold JPEG images. JFIF (the JPEG File Interchange Format) and Exif are the two standard file layouts for JPEG: image editors mostly save JFIF, while cameras write Exif, which also carries details such as the date and camera settings. Some upload forms and older apps accept only .jpg or .jpeg, and the JFIF to PNG converter turns a .jfif file into a PNG or a JPG that any app takes.

Renaming .jpeg to .jpg, or back

Changing the ending is safe, because a JPEG is recognized by its content: every JPEG file starts with the same few bytes, whatever its name. To rename one:

Renaming works only between names for the same format. A PNG, HEIC or WebP picture renamed to .jpg stays a PNG, HEIC or WebP inside, and a strict app or form may still refuse it. Convert those instead: PNG to JPG, HEIC to JPG for iPhone photos, or the WebP converter, which saves JPG too.

When a form says your file isn't a JPG

JPG and PNG are the real choice

The ending never matters; the format does. JPG makes photos small by discarding detail you barely see, while PNG keeps every pixel and can be transparent, which suits logos, screenshots and cutouts. PNG vs JPG explains when to use each.

Frequently asked questions

Is JPG the same as JPEG?

Yes. Both endings mark the same JPEG image format, and the official registration of the format's media type, image/jpeg, lists both jpg and jpeg as its file extensions.

Which is better, JPG or JPEG?

Neither. The ending doesn't change the picture. Quality depends on the compression setting chosen when the image was saved, not on whether the name ends in .jpg or .jpeg.

Can I change a .jpeg file to .jpg?

Yes. Renaming the ending changes only the file's name, so nothing is lost and apps open it the same way. Show file name extensions first, so you edit the ending instead of adding a second one.

Does converting JPEG to JPG lose quality?

Renaming loses nothing. Opening the picture and saving it again as a new JPG compresses it a second time, which can lose a little detail, so rename when only the ending needs to change.

Is JFIF the same as JPG?

A .jfif file is a JPEG image with a different ending. JFIF is one of the two standard file layouts for JPEG images, so renaming the file to .jpg usually makes a picky app open it.

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