Most of the looping clips people send today are not GIF files at all. They are silent video files wearing an old disguise. This episode tells the story of the real Graphics Interchange Format, released in June 1987 by a CompuServe team led by Steve Wilhite, when customers paid by the minute and a single color image could take minutes to arrive. The solution was a palette of 256 colors chosen from roughly 16.7 million, LZW compression that built a shared dictionary of patterns on the fly, and interlacing that let users see a rough image early and abort a wrong download.

The 1989 update added transparency and multiple frames, and in 1995 Netscape Navigator 2.0 made those frames loop forever. Then Unisys realized the compression algorithm was covered by its patent and began demanding licensing fees, provoking protests and the creation of a free alternative. The format outlived the patents and a long fight over its pronunciation, even as social platforms quietly replaced the files themselves with far smaller video.

• Limiting images to 256 colors matched the hardware of 1987, when graphics cards rarely displayed more than that at once.
• A true color hack split photos into 16 by 16 pixel blocks, each a separate frame with its own palette, which some browsers then flashed tile by tile.
• In 1999, Unisys said some non-commercial site owners could owe $5,000 to $7,500, prompting Burn All GIFs Day.
• PNG was developed in 1995 with the open deflate algorithm to avoid the patent, which expired between 2003 and 2004.
• Wilhite used his 2013 Webby Awards lifetime achievement speech to flash a message that it is pronounced with a soft G, like the peanut butter.