<use>

The <use> element takes nodes from within the SVG document, and duplicates them somewhere else.

html,body,svg { height:100% }

<svg viewBox="0 0 30 10" xmlns="http://www.w3.org/2000/svg">
  <circle id="myCircle" cx="5" cy="5" r="4" stroke="blue"/>
  <use href="#myCircle" x="10" fill="blue"/>
  <use href="#myCircle" x="20" fill="white" stroke="red"/>
  <!--
stroke="red" will be ignored here, as stroke was already set on myCircle.
Most attributes (except for x, y, width, height and (xlink:)href)
do not override those set in the ancestor.
That's why the circles have different x positions, but the same stroke value.
  -->
</svg>

The effect is the same as if the nodes were deeply cloned into a non-exposed DOM, then pasted where the use element is, much like cloned template elements in HTML5.

Most attributes on use do not override those already on the element referenced by use. (This differs from how CSS style attributes override those set 'earlier' in the cascade). Only the attributes x, y, width, height and href on the use element will override those set on the referenced element. However, any other attributes not set on the referenced element will be applied to the use element.

Since the cloned nodes are not exposed, care must be taken when using CSS to style a use element and its cloned descendants. CSS properties are not guaranteed to be inherited by the cloned DOM unless you explicitly request them using CSS inheritance.

For security reasons, browsers may apply the same-origin policy on use elements and may refuse to load a cross-origin URL in the href attribute. There is currently no defined way to set a cross-origin policy for use elements.

href

The URL to an element/fragment that needs to be duplicated. Value type: <URL> ; Default value: none; Animatable: yes

xlink:href

Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.

An <IRI> reference to an element/fragment that needs to be duplicated. Value type: <IRI> ; Default value: none; Animatable: yes

x

The x coordinate of the use element. Value type: <coordinate> ; Default value: 0; Animatable: yes

y

The y coordinate of the use element. Value type: <coordinate> ; Default value: 0; Animatable: yes

width

The width of the use element. Value type: <length> ; Default value: 0; Animatable: yes

height

The height of the use element. Value type: <length> ; Default value: 0; Animatable: yes

Core Attributes

Most notably: id, tabindex

Styling Attributes

class, style

Conditional Processing Attributes

Most notably: requiredExtensions, systemLanguage

Event Attributes

Global event attributes, Graphical event attributes

Presentation Attributes

Most notably: clip-path, clip-rule, color, color-interpolation, color-rendering, cursor, display, fill, fill-opacity, fill-rule, filter, mask, opacity, pointer-events, shape-rendering, stroke, stroke-dasharray, stroke-dashoffset, stroke-linecap, stroke-linejoin, stroke-miterlimit, stroke-opacity, stroke-width, transform, vector-effect, visibility

ARIA Attributes

aria-activedescendant, aria-atomic, aria-autocomplete, aria-busy, aria-checked, aria-colcount, aria-colindex, aria-colspan, aria-controls, aria-current, aria-describedby, aria-details, aria-disabled, aria-dropeffect, aria-errormessage, aria-expanded, aria-flowto, aria-grabbed, aria-haspopup, aria-hidden, aria-invalid, aria-keyshortcuts, aria-label, aria-labelledby, aria-level, aria-live, aria-modal, aria-multiline, aria-multiselectable, aria-orientation, aria-owns, aria-placeholder, aria-posinset, aria-pressed, aria-readonly, aria-relevant, aria-required, aria-roledescription, aria-rowcount, aria-rowindex, aria-rowspan, aria-selected, aria-setsize, aria-sort, aria-valuemax, aria-valuemin, aria-valuenow, aria-valuetext, role

XLink Attributes

xlink:href, xlink:title