If you're looking for a good image optimization product, I've had excellent results from ImageOptim (I have no affiliation with them). They have a free Mac App, they have an API service, but also they kindly link to lots of other free similar products and services: https://imageoptim.com/versions.html
If you can spare the CPU cycles (depending on how you optimize, they can actually be expensive) and if your images will be downloaded frequently, your users will thank you.
If you can spare the CPU cycles (depending on how you optimize, they can actually be expensive) and if your images will be downloaded frequently, your users will thank you.