Element: transitionrun event
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since March 2020.
The transitionrun event is fired when a CSS transition is first created, i.e., before any transition-delay has begun.
This event is not cancelable.
Syntax
Use the event name in methods like addEventListener(), or set an event handler property.
Event type
A TransitionEvent. Inherits from Event.
Event properties
Also inherits properties from its parent Event.
TransitionEvent.propertyNameRead only-
A string containing the name CSS property associated with the transition.
TransitionEvent.elapsedTimeRead only-
A
floatgiving the amount of time the transition has been running, in seconds, when this event fired. This value is not affected by thetransition-delayproperty. TransitionEvent.pseudoElementRead only-
A string, starting with
::, containing the name of the pseudo-element the animation runs on. If the transition doesn't run on a pseudo-element but on the element, an empty string:''.
Examples
This code adds a listener to the transitionrun event:
The same, but using the ontransitionrun property instead of addEventListener():
Live example
In the following example, we have a simple <div> element, styled with a transition that includes a delay:
To this, we'll add some JavaScript to indicate where the transitionstart and transitionrun events fire.
The difference is that:
transitionrunfires when the transition is created (i.e., at the start of any delay).transitionstartfires when the actual animation has begun (i.e., at the end of any delay).
The transitionrun will occur even if the transition is canceled before the delay expires. If there is no transition delay or if transition-delay is negative, both transitionrun and transitionstart are fired.
Specifications
| Specification |
|---|
| CSS Transitions # transitionrun |
Browser compatibility
See also
- The
TransitionEventinterface - CSS properties:
transition,transition-delay,transition-duration,transition-property,transition-timing-function - Related events:
transitionend,transitionstart,transitioncancel