From http://www.w3schools.com (Copyright Refsnes Data)

HTML 5 <base> tag

Definition and Usage

The base element specifies a base URL for all the links in a page.

Differences Between HTML 4.01 and HTML 5

None

Tips and Notes

Note: The <base> tag must go inside the head element.

Note: Maximum one <base> element in a document.

Example

Assume that the absolute address for an image is:

<img src="http://www.w3schools.com/images/smile.gif" />

Now we insert the <base> tag, which specifies a base URL for all of the links in a page, in the head section of a page:

<head>
<base href="http://www.w3schools.com/images/" />
</head>

When inserting images on the page in the example above, we just have to specify the relative address, and the browser will look for that file using the full URL, "http://www.w3schools.com/images/smile.gif": 

<img src="smile.gif" />

Attributes

Attribute Value Description 5 4
href URL Specifies the URL to use as the base URL for links in the page 4 5
target _blank
_parent
_self
_top		 Where to open all the links on the page. This attribute can be overridden by using the target attribute in each link.
  • _blank - all the links will open in new windows
  • _self - all the links will open in the same frame they where clicked
  • _parent - all the links will open in the parent frameset
  • _top - all the links will open in the full body of the window
 4 5

Standard Attributes and Events

NONE

Try-It-Yourself Demos

One target for all links
How to use the <base> tag to let all the links on a page have the same target.

From http://www.w3schools.com (Copyright Refsnes Data)