When running Chrome Lighthouse I get warning on my images sizes. It says I could adapt image sizes according to the user device. At the moment my images are the largest possible and resized according to any bootstrap grid change ...
It works pretty well but needs the larger file format being downloaded whatever the user device.
I can of course add an image replacement tag in a media query... But my question is: would all the pictures not be loaded instead of a single image ?
I think I have found the solution of adding different CSS files depending of the media size, but this thread Media Queries to load resource? suggests that I would lose responsiveness ...
I am a bit lost in understanding how images or other assets are loaded by the browser in case they belong to the same CSS file ...