Meta elements are HTML or XHTML elements used to provide structured metadata about a Web page. Such elements must be placed as tags in the head section of an HTML or XHTML document. Meta elements can be used to specify page description, keywords and any other metadata not provided through the other head elements and attributes.

The meta element has four valid attributes: content, http-equiv, name and scheme. Of these, only content is a required attribute.

An example of the use of the meta element

In one form, meta elements can specify HTTP headers which should be sent before the actual content when the HTML page is served from Web server to client. For example: This specifies that the page should be served with an HTTP header called 'Content-Type' that has a value 'text/html'. This is a typical use of the meta element, which specifies the document type so a client (browser or otherwise) knows what content type to render.

In the general form, a meta element specifies name and associated content attributes describing aspects of the HTML page. For example: In this example, the meta element identifies itself as containing the 'keywords' relevant to the document, Wikipedia and encyclopedia.

Meta tags can be used to indicate the location a business serves: In this example, geographical information is given according to zip codes.

Meta element used in search engine optimization

Meta elements provide information about a given Web page, most often to help search engines categorize them correctly. They are inserted into the HTML document, but are often not directly visible to a user visiting the site.

They have been the focus of a field of marketing research known as search engine optimization (SEO), where different methods are explored to provide a user's site with a higher ranking on search engines. In the mid to late 1990s, search engines were reliant on meta data to correctly classify a Web page and webmasters quickly learned the commercial significance of having the right meta element, as it frequently led to a high ranking in the search engines — and thus, high traffic to the website.

As search engine traffic achieved greater significance in online marketing plans, consultants were brought in who were well versed in how search engines perceive a website. These consultants used a variety of techniques (legitimate and otherwise) to improve ranking for their clients.

Meta elements have significantly less effect on search engine results pages today than they did in the 1990s and their utility has decreased dramatically as search engine robots have become more sophisticated. This is due in part to the nearly infinite re-occurrence (keyword stuffing) of meta elements and/or to attempts by unscrupulous website placement consultants to manipulate (spamdexing) or otherwise circumvent search engine ranking algorithms.