by

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since January 2020.

The by attribute specifies a relative offset value for an attribute that will be modified during an animation.

The starting value for the attribute is either indicated by specifying it as value for the attribute given in the attributeName or the from attribute.

You can use this attribute with the following SVG elements:

Example

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

html

<svg viewBox="0 0 200 200" xmlns="http://www.w3.org/2000/svg">
  <rect x="10" y="10" width="100" height="100">
    <animate attributeName="width" fill="freeze" by="50" dur="3s" />
  </rect>
</svg>

Usage notes

Value	See below
Default value	None
Animatable	No

The exact value type for this attribute depends on the value of the attribute that will be animated.

When a list of values is defined via the values attribute, the by attribute is ignored.

Specifications

Specification
SVG Animations Level 2 # ByAttribute

Browser compatibility

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