W3cubDocs

/HTML

<base>

A document's used base URL can be accessed by scripts with document.baseURI. If the document has no <base> elements, then baseURI defaults to location.href.

Content categories Metadata content.
Permitted content None, it is an empty 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

This element's attributes include the global attributes.

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.

href
The base URL to be used throughout the document for relative URLs. Absolute and relative URLs are allowed.
target
A keyword or author-defined name of the default browsing context to show the results of navigation from <a>, <area>, or <form> elements without explicit target attributes.
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

If multiple <base> elements are used, only the first href and first target are obeyed — all others are ignored.

In-page anchors

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:

  1. Given <base href="https://example.com">
  2. ...and this link: <a href="#anchor">Anker</a>
  3. ...the link points to https://example.com/#anchor.

Open Graph

Open Graph tags do not acknowledge <base>, and should always have full absolute URLs. For example:

<meta property="og:image" content="https://example.com/thumbnail.jpg">

Examples

<base href="https://www.example.com/">
<base target="_blank"> 
<base target="_top" href="https://example.com/">  

Specifications

Specification Status Comment
HTML Living Standard
The definition of '<base>' in that specification.
Living Standard No change since last snapshot.
HTML5
The definition of '<base>' in that specification.
Recommendation Specified the behavior of target
HTML 4.01 Specification
The definition of '<base>' in that specification.
Recommendation Added the target attribute

Browser compatibilityUpdate compatibility data on GitHub

Desktop
Chrome Edge Firefox Internet Explorer Opera Safari
base Yes 12 1 Yes
Yes
Before Internet Explorer 7, <base> can be positioned anywhere in the document and the nearest value of <base> is used.
Yes Yes
href Yes 12 1 Yes Yes Yes
target Yes 12 Yes Yes Yes Yes
Mobile
Android webview Chrome for Android Firefox for Android Opera for Android Safari on iOS Samsung Internet
base Yes Yes 4 Yes Yes Yes
href Yes Yes 4 Yes Yes Yes
target Yes Yes Yes Yes Yes Yes

© 2005–2020 Mozilla and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base