I've just noticed this demo exposes a Firefox bug with image scaling that I'm quite surprised to see. Not related to lazy loading, but may be of interest. Bug:

I've just noticed this demo exposes a Firefox bug with image scaling that I'm quite surprised to see. Not related to lazy loading, but may be of interest. Bug: When the same image is found elsewhere on the page, Firefox doesn't bother using smooth interpolation when downscaling. [Edit - workaround is to avoid cache, as in cat.jpg?01 ; cat.jpg?02 ] Look at the cat's whiskers, they look rough in the smallest image. They should look smooth. So using Firebug I removed all other images on the page except the first smallest version. Hey presto, the whiskers are suddenly smooth. http://ivopetkov.github.io/responsivelyLazy/ http://ivopetkov.github.io/responsivelyLazy/ Of course, IE is a lot worse - its scaling is rough all the time regardless.