AnimationEffectTimingProperties

The AnimationEffectTimingProperties dictionary, part of the Web Animations API, is used by Element.animate(), KeyframeEffectReadOnly(), and KeyframeEffect() to describe timing properties for animation effects. These properties are all optional, although without setting a duration the animation will not play.

Simply put, these properties describe how the user agent should go about making the transition from from keyframe to keyframe, and how to behave when the animation begins and ends.

Properties

delay Optional

The number of milliseconds to delay the start of the animation. Defaults to 0.

direction Optional

Whether the animation runs forwards (normal), backwards (reverse), switches direction after each iteration (alternate), or runs backwards and switches direction after each iteration (alternate-reverse). Defaults to "normal".

duration Optional

The number of milliseconds each iteration of the animation takes to complete. Defaults to 0. Although this is technically optional, keep in mind that your animation will not run if this value is 0.

easing Optional

The rate of the animation's change over time. Accepts the pre-defined values "linear", "ease", "ease-in", "ease-out", and "ease-in-out", or a custom "cubic-bezier" value like "cubic-bezier(0.42, 0, 0.58, 1)". Defaults to "linear".

endDelay Optional

The number of milliseconds to delay after the end of an animation. This is primarily of use when sequencing animations based on the end time of another animation. Defaults to 0. 

fill Optional

Dictates whether the animation's effects should be reflected by the element(s) prior to playing ("backwards"), retained after the animation has completed playing ("forwards"), or both. Defaults to "none".

iterationStart Optional

Describes at what point in the iteration the animation should start. 0.5 would indicate starting halfway through the first iteration for example, and with this value set, an animation with 2 iterations would end halfway through a third iteration. Defaults to 0.0.

iterations Optional

The number of times the animation should repeat. Defaults to 1, and can also take a value of Infinity to make it repeat for as long as the element exists.

Specifications

Browser compatibility

[1] The Web Animations API is only enabled by default in Firefox Developer Edition and Nightly builds. You can enable it in beta and release builds by setting the preference dom.animations-api.core.enabled to true, and can disable it in any Firefox version by setting this preference to false.

See also

• Web Animations API
• Using the Web Animations API
• Element.animate()
• KeyframeEffect()
• KeyframeEffectReadOnly()