Sarah Jane's Alien Files (also known as SJA Alien Files, formerly The Alien Files) was a series spun off from The Sarah Jane Adventures. It started during the programme's third series as a series of webisodes on the programme's website, similar to the Monster Files. During The Sarah Jane Adventures Series 4, it became a half-hour spin-off show featuring more thorough detail of past Sarah Jane Adventures aliens and recaps of the episodes in which they appeared.