from

The from attribute indicates the initial value of the attribute that will be modified during the animation.

When used with the to attribute, the animation will change the modified attribute from the from value to the to value. When used with the by attribute, the animation will change the attribute relatively from the from value by the value specified in by.

You can use this attribute with the following SVG elements:

• <animate>
• <animateMotion>
• <animateTransform>

html,
body,
svg {
  height: 100%;
}

<svg viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg">
  <rect x="10" y="10" height="100">
    <animate attributeName="width" fill="freeze" from="100" to="150" dur="3s" />
  </rect>
</svg>