Motion JPEG, also known as M-JPEG, is a video file format consisting of a sequence of individual JPEG images; unlike other video compression algorithms, each frame is an image unto itself. Often used by Video disc jockeys and multimedia artists.

M-JPEG is normally used in HTTP streams by using the multipart/x-mixed-replace content type which separates each image into individual HTTP replies separated by an agreed marker. Mozilla based browsers like Netscape and Firefox have native support for viewing these streams whereas Internet Explorer does not.

There is no standard file format for Motion JPEG which can make storing and handling the format a pain.