It is used to specify the base URL used in all relative URLs of a document and/or the default target attribute. It must therefore have at least one
target attribute defined, being able to have both.
There can only be one
<base> element per document and it has to be inside the
<head>. If there is more than one, only the first
target will be taken into account, the rest will be ignored.
If either of these two attributes is defined, the
<base> element must appear before other elements with attribute values that contain URLs, such as a
<link href = "">.
It has two attributes:
href: the base URL that will be used throughout the entire document in relative URLs. It can take the value of an absolute or relative URL.
target: a keyword that defines the navigation context in which to display the navigation results of
<form>elements that do not have a
targetattribute explicitly defined. It can have the following values:
_self: shows the result in the same navigation context. It is the default value.
_blank: displays the result in a new, unnamed navigation context.
_parent: shows the result in the navigation context of the parent of the current one if the current page is within a frame. If there is no parent, it acts the same as
_top: shows the resource in the highest navigation context that is an ancestor of the current one. If there is no parent, it acts the same as
Internal links to a document fragment, for example
<a href="#id-example"> are resolved using
<base>, triggering an HTTP request to the base URL with the fragment appended. For instance:
<base href = "https://example.com">
- ...and this link:
- ...the link points to
Open Graph tags don't recognize the
<base> element, so they should always have absolute URLs. For instance:
<meta property="og:image" content="https://example.com/thumbnail.jpg">
- Type: -
- Self-closing: Yes
- Semantic value: No