Footer comics

The bottom segment on xkcd.com

The footer comics are likely selected for representing the topics covered on xkcd. These comics can be often described as heavily representational of the comic itself. They are:

150: Grownups | 730: Circuit Diagram | 162: Angular Momentum | 688: Self-Description | 556: Alternative Energy Revolution

1732: Earth Temperature Timeline

Changes to footer comics

• On February 7, 2006 the first footer comics were available. It featured 40, 49, 37, 44 & 10, in that order.
• On April 8, 2006 the first one changed to 77.
• On October 13, 2006 it changed to current style, although still only the five top footer comics, and with 150, 123, 162, 55 & 77, rather than the current set of five.
• On August 17, 2010 it changed three of the comics leaving 150, 730, 162, 688, 556. Those five are all still there.
• On March 1, 2019 it changed to the current version by including 1732: Earth Temperature Timeline below the other five comics. The new addition was included as one long image taking up the same space as the other five comics.