SVGAnimationElement - Web APIs
svganimationelement.beginelement() creates a begin instance time for the current time.
...the behavior of this method is equivalent to beginelementat(0).
... svganimationelement.beginelementat() creates a begin instance time for the current time plus the specified offset.

begin - SVG: Scalable Vector Graphics
indefinite the begin of the animation will be determined by a beginelement() method call or a hyperlink targeted to the element.

restart - SVG: Scalable Vector Graphics
> <rect x="120" y="30" width="100" height="100"> <animate attributetype="xml" attributename="y" from="30" to="100" dur="5s" repeatcount="1" restart="whennotactive"/> </rect> <a id="restart"><text y="20">restart animation</text></a> </svg> document.getelementbyid("restart").addeventlistener("click", evt => { document.queryselectorall("animate").foreach(element => { element.beginelement(); }); }); usage notes value always | whennotactive | never default value always animatable no always this value indicates that the animation can be restarted at any time.