[css3-transitions] transition-duration: 0 versus animation-duration: 0s;

When an animation last 0s, and therefore is not perceptible, it still occurs. Both an animationstart and animationend occur, though no animationiteration occurs, even if there are 100 iterations of 0 seconds each. Additionally, animation-fil-mode: forwards and both will both leave the element on the 100% keyframe.

This is not what happens with transitions.

>> By default the value is 0s, meaning that the transition is immediate (i.e. there will be no animation). 

there is still a transition, just no animation of that transition.
the animationend event does not occur currently in browsers. 
I am not sure if that sentence is clearly stating the animation is not occurring and therefore no transitionend event should occur. Whether or not that is what it is stating, I think the transitionend event should still occur. The property values are still transitioning. They’re just doing so over 0ms, just like with the animation of 0s. The default  for animation-duration is 0s, not ‘no animation’

I think consistency between CSS animation and CSS transitions is important. To me this feels inconsistent. Thoughts? (or has this been hashed out, and i missed the convo?)

Note that if there is a delay greater than 0ms on the transition, but a default duration of 0s, the transitionend does occur.

-Estelle 

Estelle Weyl
estelle@weyl.org
http://www.standardista.com