Here's a little something from the team at imgix that I think would resonate well with the DN audience. Let us know what you think!
Pretty nice, but it would be good if it said something about retina images. That the image doesn't fit the container doesn't really matter in these days.
I would argue quite the opposite. Given HTML5 options like srcset and the picture element, it's possible to not serve Retina images only to devices that need them. Excess pixels in images is the #1 driver for page bloat, so it can have a big effect on your user experience.
We've got a nice tutorial on srcset here: https://docs.imgix.com/tutorials/responsive-images-srcset-imgix
Nice tool, though maybe a bit too aggressive on the optimisation front? It's recommendations would cause a marked drop in quality for a lot of images.
There's obviously some stuff that's hard to account for e.g. it hated the animation sprite in the hero here. We do want to make it more efficient but switching it out to a single PNG isn't really an option.
On the quality drop: we are a bit aggressive there but provide you with a few options with the image picker. You should be able to find something that straddles the line between quality and file size.
Good catch on the sprited PNG. That is not a case we currently account for!