Speed Index vs. above fold animations

Let’s say a website has some introductory animation above the fold, eg. an image fades in, then a heading slides in, etc. Normally those elements would appear at some moment but now they are delayed by the animation duration. Does this affect Speed Index?


If there’s a large enough visual change, which it does sound like, then yes.

Yes, thank you.

In the meanwhile I’ve set up a test to verify this, just haven’t got to answering my own question here yet:

Test page without animation:

Test result:

Test page with animation:

Test result:

There are 3 animations taking 2 seconds together, which almost doubled the speed index result.