HTML Uniform Resource Locators

A URL is another word for a web address.

A URL can be composed of words (w3ii.com), or an Internet Protocol (IP) address (192.68.20.50).

Most people enter the name when surfing, because names are easier to remember than numbers.

URL - Uniform Resource Locator

Web browsers request pages from web servers by using a URL.

When you click on a link in an HTML page, an underlying <a> tag points to an address on the web.

A Uniform Resource Locator (URL) is used to address a document (or other data) on the web.

A web address, like http://www.w3ii.com/html/default.html follows these syntax rules:

Explanation:

• scheme - defines the type of Internet service (most common is http)
• prefix - defines a domain prefix (default for http is www)
• domain - defines the Internet domain name (w3ii.com)
• port - defines the port number at the host (default for http is 80)
• path - defines a path at the server (If omitted: the root directory of the site)
• filename - defines the name of a document or resource

Common URL Schemes

The table below lists some common schemes:

URL Encoding

URLs can only be sent over the Internet using the ASCII character-set. If a URL contains characters outside the ASCII set, the URL has to be converted.

URL encoding converts non-ASCII characters into a format that can be transmitted over the Internet.

URL encoding replaces non-ASCII characters with a "%" followed by hexadecimal digits.

URLs cannot contain spaces. URL encoding normally replaces a space with a plus (+) sign, or %20.

Try It Yourself

If you click "Submit", the browser will URL encode the input before it is sent to the server.

A page at the server will display the received input.

Try some other input and click Submit again.

ASCII Encoding Examples

Your browser will encode input, according to the character-set used in your page.

The default character-set in HTML5 is UTF-8.

For a complete reference of all URL encodings, visit our URL Encoding Reference.