.jfif File — JPEG File Interchange Format

JFIF (JPEG File Interchange Format) is a minimal file format specification that defines how JPEG-compressed image data should be stored in a file for interchange between applications. JFIF was introduced in 1991 to standardize the storage of JPEG data, which the JPEG standard itself does not specify — JPEG defines only the compression algorithm. JFIF adds a small header containing version information, resolution/aspect ratio data, and an optional thumbnail before the JPEG data stream. While the .jfif extension is technically more precise than .jpg for files following this specification, the extension is relatively uncommon. Most JPEG files on the web and in digital cameras actually follow either the JFIF or EXIF specification for their container format, but use the .jpg or .jpeg extension regardless. The .jfif extension is sometimes seen in files downloaded from Microsoft Edge and certain Windows applications. For all practical purposes, .jfif files are standard JPEG images that can be renamed to .jpg without any conversion or data modification.