My site is running quite slow so I put it into gtmatrix and found out that one of the biggest reasons is that I need to optimize my images.
I used medium size images on the article, which can be clicked to show the larger version, from what I understand gtm is telling me the site is loading all the larger images just to show the smaller ones and I need to change this, but other than uploading 2 different sized images and linking them one by one how can I do this?
To be honest Im quite amazed wordpress is not already setup to do this :/