[svgwg] Status of animVal deprecation (#1100)

nikolaszimmermann has just created a new issue for https://github.com/w3c/svgwg:

== Status of animVal deprecation ==
SVG2, more than a decade ago, made 'animVal' an alias of 'baseVal' - to make all our lives much easier and _greatly_ reduce the complexity of implementing SVG DOM. Furthermore, animVal was originally about reflecting SMIL animations in the DOM, there is no good story for CSS Animations/Transitions/WebAnimations etc. and no intent to make a good story, simply because there is no author demand for this kind of reflection.

Therefore I'd support to finally drop animVal, however, @shallawa made this testcase:

```
<svg width="300" height="150" xmlns="http://www.w3.org/2000/svg">
  <title>Attribute Animation with SMIL</title>
  <circle cx="0" cy="50" r="15" fill="blue" stroke="black" stroke-width="1">
    <animate
      attributeName="cx"
      from="0"
      to="500"
      dur="5s"
      repeatCount="indefinite" />
  </circle>
  <text x="10" y="100"></text>
  <text x="10" y="120"></text>
  <script>
    (function repeatOften() {
      let circle = document.querySelector("circle")
      let text = document.querySelectorAll("text");
      text[0].innerHTML = "circle.cx.baseVal = " + circle.cx.baseVal.valueAsString;
      text[1].innerHTML = "circle.cx.animVal = " + circle.cx.animVal.valueAsString;
      requestAnimationFrame(repeatOften);
    })();
  </script>
</svg>```

demonstrating that in all current browser engines, animVal is still reflecting the SMIL-animated values in every rAF(). What do we do?

Shall we contact all vendors to make a coordinated move to remove animVal support from all the engines? Let's discuss this in the next call.

Please view or discuss this issue at https://github.com/w3c/svgwg/issues/1100 using your GitHub account


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Received on Monday, 27 April 2026 19:38:30 UTC