Why Use Interlaced Images?

Interlacing is a form of incremental decoding, because the image can be loaded incrementally. ... Also, the benefits of interlacing to those on low-speed connections may be outweighed by having to download a larger file, as interlaced images typically do not compress as well.

Why you might want to use an interlaced image?

> Interlaced images are much more easily view-able. The interlace lets you see the picture before all the data has been transmitted (makes them appear faster and better-looking) and gives you the "feeling" that it is being downloaded faster.

Is interlaced PNG better?

Interlaced image loads an early degraded version of the whole image as soon as possible and then progressively renders the image to clear state. Interlaced will almost always be a bit bigger in filesize. Non-interlaced image will load up in tiles showing clear image in each tile as it progresses to load in the image.