<base>: The Document Base URL element #
::: section-content
The <base>
HTML element specifies the base URL to use for
all relative URLs in a document. There can be only one <base>
element in a document.
A document's used base URL can be accessed by scripts with
Node.baseURI.
If the document has no <base> elements, then baseURI defaults to
location.href.
| Content categories | Metadata content. |
|---|---|
| Permitted content | None; it is a void element. |
| Tag omission | There must be no closing tag. |
| Permitted parents | A <head> that doesn't contain
another <base>
element. |
| Implicit ARIA role | No corresponding role |
| Permitted ARIA roles | No role permitted |
| DOM interface | HTMLBaseElement |
Attributes #
::: section-content This element's attributes include the global attributes.
::: {#sect1 .notecard .warning}
Warning: If either of the following attributes are specified, this
element must come before other elements with attribute values of
URLs, such as
<link>'s href attribute.
:::
hrefThe base URL to be used throughout the document for relative URLs. Absolute and relative URLs are allowed.
data:andjavascript:URLs are not allowed.targetA keyword or author-defined name of the default browsing context to show the results of navigation from
<a>,<area>, or<form>elements without explicittargetattributes. The following keywords have special meanings:_self(default): Show the result in the current browsing context._blank: Show the result in a new, unnamed browsing context._parent: Show the result in the parent browsing context of the current one, if the current page is inside a frame. If there is no parent, acts the same as_self._top: Show the result in the topmost browsing context (the browsing context that is an ancestor of the current one and has no parent). If there is no parent, acts the same as_self. :::
Usage notes #
Multiple <base> elements #
::: section-content
If multiple <base> elements are used, only the first href and first
target are obeyed — all others are ignored.
:::
In-page anchors #
::: section-content
Links pointing to a fragment in the document — e.g.
<a href="#some-id"> — are resolved with the <base>, triggering an
HTTP request to the base URL with the fragment attached.
For example, given <base href="https://example.com/"> and this link:
<a href="#anchor">To anchor</a>. The link points to
https://example.com/#anchor.
:::
Open Graph #
::: section-content
Open Graph{target="_blank"} tags do not acknowledge
<base>, and should always have full absolute URLs. For example:
::: code-example [html]{.language-name}
<meta property="og:image" content="https://example.com/thumbnail.jpg" />
::: :::
Examples #
::: section-content ::: code-example [html]{.language-name}
<base href="https://www.example.com/" />
<base target="_blank" />
<base target="_top" href="https://example.com/" />
::: :::
Specifications #
::: _table #
Specification #
HTML Standard
[#
the-base-element]{.small}
:::
Browser compatibility #
::: _table #
Desktop Mobile
Chrome Edge Firefox Internet Opera Safari WebView Chrome Firefox Opera Safari Samsung
Explorer Android Android for Android on IOS Internet
Android
base 1 12 1 Yes 15 3 4.4 18 4 14 2 1.0
Before
Internet
Explorer 7,
`<base>` can
be
positioned
anywhere in
the document
and the
nearest
value of
`<base>` is
used.
href 1 12 1 Yes 15 3 4.4 18 4 14 2 1.0
target 1 12 1 Yes 15 3 4.4 18 4 14 2 1.0
#
:::
::: _attribution
© 2005–2023 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5
or later.
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base{._attribution-link}
:::