Are images generated on the fly while using contextual image delivery or is it stored somewhere in advance. I am looking for options to deliver device specific images to content delivery without creating multiple images for different devices. Also want to know if the contextual image delivery engine generate the images on the fly, is there any performance issue?
- On the fly but cached so subsequent requests are fast.
- There could be some slightly delay for first user, but same can be compensated in image download as size would be small, it also depends volume of images being used on your web page.
refer this execellent blog post