A lot of WordPress users assume, rightly, that images they've uploaded are compressed and optimized for the web.
This assumption is mostly true, but sometimes poorly-compressed or oversized images will slip through. We can't expect every website user to know the intricasies of image compression, and it's not unreasonable to expect that WordPress should make all uploaded images work correctly.
So let's do that. Here's how to make sure every image uploaded to WordPress is optimized.