Base Tags in HTML5

Introduction

A Base tag provides a default (base) URL or relative links. It is usually used to set a default URL for all subsequent relative links. Relative links can be a stylesheet, source of script tag and hrefs in the anchor tag. In simple terms, you can say a base tag sets a default address or a default target for all links on a page.

One important thing that you should always remember is that a base tag must be within the head tag and it must be the first tag in the head tag. You can use only one base tag in a document and you must use the href attribute, target attribute or both.

Standard Syntax

<base
href="URL"
target="frame or window name | _blank | _parent | _self |_top">

Examples

<base href="http:// www.c-sharpcorner.com/">
<base target="_blank" href="http:// www.c-sharpcorner.com/">

Attributes Introduced by HTML5

Values	Description
accesskey	spaced list of accelerator key(s)
contenteditable	true \| false \| inherit
contextmenu	id of menu
data-X	user-defined data
draggable	true \| false \| auto
hidden	hidden
itemid	microdata id in URL format
itemprop	microdata value
itemref	space-separated list of IDs that may contain microdata
itemscope	itemscope
itemtype	microdata type in URL format
spellcheck	true \| false"
tabindex	number

HTML5 Event Attributes
onabort	onblur	oncanplay	oncanplaythrough	onchange
onclick	oncontextmenu	ondblclick	ondrag	ondragend
ondragenter	ondragleave	ondragover	ondragstart	ondrop
ondurationchange	onemptied	onended	onerror	onfocus
onformchange	onforminput	oninput	oninvalid	onkeydown
onkeypress	onkeypress	onkeyup	onload	onloadeddata
onloadedmetadata	onloadstart	onmousedown	onmousemove	onmouseout
onmouseover	onmouseup	onmousewheel	onpause	onplay
onplaying	onprogress	onratechange	onreadystatechange	onscroll
onseeked	onseeking	onselect	onshow	onstalled
onsubmit	onsuspend	ontimeupdate	onvolumechange	onwaiting

Attributes Defined by Internet Explorer

id="unique alphanumeric identifier" (4)

Events Defined by Internet Explorer

onlayoutcomplete,
onmouseenter,
onmouseleave,
onreadystatechange

HTMLPage.htm

<!DOCTYPE html>
<html>
<head>
<base href="http://www.c-sharpcorner.com/"/>
<title></title>
</head>
<body>
<header>
<P>Hi... Freinds.
</header>
<p>I am using a base tag in this article. Before starting anything, I want to share something with you. I got much knowledge of Asp.net from
<a href="/Articles/ArticleListing.aspx?SectionID=1&SubSectionID=75">csharpcorner</a> site. I am in touch with
<a href="">csharpcorner</a>from long time. You are definitely surprised that why I am sharing with you.Actually I got confuse that which example I should use to explain base tag. In this article i have applied base tag on
<a href="">csharpcorner</a> word that will navigate you to
<a href="">csharpcorner</a> website. When you click on
<a href="/UploadFile/667ddf/8187/">area tag</a> you will navigate to my article.
</P>
</body>
</html>

Output

Internet Explorer

Chrome

FireFox

Safari