> Compressing an already-compressed file can make it bigger due to metainfo That's not why, that's just a reason why doing so is silly. > the gzip algorithm i

> Compressing an already-compressed file can make it bigger due to metainfo That's not why, that's just a reason why doing so is silly. > the gzip algorithm isn't optimised as well for images as say, jpeg. gzip is used in PNG. Read the article; the reason is because he wasn't sending gzip data, just deflate data.