Example
Describe metadata within an HTML document:
<head>
<meta charset="UTF-8">
<meta name="description" content="Free Web tutorials">
<meta name="keywords" content="HTML,CSS,XML,JavaScript">
<meta name="author" content="John Doe">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<meta charset="UTF-8">
<meta name="description" content="Free Web tutorials">
<meta name="keywords" content="HTML,CSS,XML,JavaScript">
<meta name="author" content="John Doe">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
Definition and Usage
Metadata is data (information) about data.The <meta> tag provides metadata about the HTML document. Metadata will not be displayed on the page, but will be machine parsable.
Meta elements are typically used to specify page description, keywords, author of the document, last modified, and other metadata.
The metadata can be used by browsers (how to display content or reload page), search engines (keywords), or other web services.
HTML5 introduced a method to let web designers take control over the viewport (the user's visible area of a web page), through the <meta> tag (See "Setting The Viewport" example below).
Tips and Notes
Note: <meta> tags always go inside the <head> element.Note: Metadata is always passed as name/value pairs.
Note: The content attribute MUST be defined if the name or the http-equiv attribute is defined. If none of these are defined, the content attribute CANNOT be defined.
Setting The Viewport
HTML5 introduced a method to let web designers take control over the viewport, through the <meta> tag.
The viewport is the user's visible area of a web page. It varies with the device, and will be smaller on a mobile phone than on a computer screen.
You should include the following <meta> viewport element in all your web pages:
<meta name="viewport" content="width=device-width,
initial-scale=1.0">
A <meta> viewport element gives the
browser instructions on how to control the page's dimensions and scaling.The width=device-width part sets the width of the page to follow the screen-width of the device (which will vary depending on the device).
The initial-scale=1.0 part sets the initial zoom level when the page is first loaded by the browser.
Differences Between HTML 4.01 and HTML5
The scheme attribute is not supported in HTML5.HTML5 has a new attribute, charset, which makes it easier to define charset:
- HTML 4.01: <meta http-equiv="content-type" content="text/html; charset=UTF-8">
- HTML5: <meta charset="UTF-8">
Differences Between HTML and XHTML
In HTML the <meta> tag has no end tag.In XHTML the <meta> tag must be properly closed.
Examples
Example 1 - Define keywords for search engines:
<meta name="keywords" content="HTML, CSS,
XML, XHTML, JavaScript">
Example 2 - Define a description of your
web page:
<meta name="description" content="Free Web
tutorials on HTML and CSS">
Example 3 - Define the author of a page:
<meta name="author" content="John
Doe">
Example 4 - Refresh document every 30
seconds:
<meta http-equiv="refresh" content="30">
Example 5 - Setting the viewport to make
your website look good on all devices:
<meta name="viewport" content="width=device-width,
initial-scale=1.0">
Attributes
New in HTML5.
|
Attribute
|
Value
|
Description
|
|
charset
|
character_set
|
Specifies
the character encoding for the HTML document
|
|
content
|
text
|
Gives the
value associated with the http-equiv or name attribute
|
|
http-equiv
|
content-type
default-style refresh |
Provides
an HTTP header for the information/value of the content attribute
|
|
name
|
application-name
author description generator keywords viewport |
Specifies
a name for the metadata
|
|
scheme
|
format/URI
|
Not supported in HTML5.
Specifies a scheme to be used to interpret the value of the content attribute |
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