Image compression question

How is ImageOptim a better image compression program than Photoshop? What are Photoshop users misunderstanding with regards to true image optimization/compression? Thanks!

Photoshop isn’t the only option :wink:

I think PS’s optimisation tools are still lacking, I regularly get images that have passed through PS’s “Save for web” feature and often still manage to shave an extra 10/20/30% through my own image editor.

Adobe was very late to the web, it didn’t even support the .jpg format without a plugin when other images editors were leading the way (read’s-bloodless-coup/ )

Do you know what the difference is? That is, what is Photoshop not doing?

I don’t know the technical differences, only the developers would be able to tell you that - it could be that ImageOptim is using more up to day methods and technologies than Adobe.