Look! It’s the history of GIFs! But first, about how you’re saying it wrong:
The issue of pronunciation – Before we get too existential about GIFs, we should probably learn how to pronounce their name. According to GIF lore, the programmers who created the GIF pronounced the acronym with a soft G, like a J. Yes, just like the peanut butter. However, according to Ficklin, the original GIF namers probably chose their counterintuitive pronunciation solely to “feed their contrarian nature. It’s a loner syndrome,” Ficklin said. He admits to having chosen the hard-G pronunciation for the same reason.