QI XL is a 45 minute episode of QI. This extended edition contains new material from the show, in addition to the 30 minutes of footage shown in the normal episode. This includes some unaired questions and some more jokes and conversation from the questions shown in QI; the XL version still contains only a small portion of the content recorded, as it takes around two hours to film each episode of QI. It usually airs later than the normal episode (often on the following day), and is sometimes broadcast on a different channel.
These editions of the show have been present in every episode since "Flotsam and Jetsam": the third episode of the F Series broadcast on 9 January 2009. This was because the show moved to BBC Two, following the Comic Relief special "Families" and the Christmas special "Fire and Freezing".