.png is great because it supports alpha channels (transparency), but that adds a lot of weight to it, png is ironically called “portable” network graphic. Converting to .jpg format reduces the size of an image by as much as 10 times! But Jpg is designed to compress images by – in simple terms – guessing where pixels should be. gif format has compression but it does not destroy image fidelity. Converting to .gif will shave your file size by at least 4 times!