HTML Uniform Resource Locators

A URL is a web page address.

A URL can consist of letters, such as “”, or an Internet Protocol (IP) address:

Most people use the website domain name to access the website, because the name is easier to remember than the number.

URL – Uniform Resource Locator

A web browser requests a page from a web server through a URL.

When you click a link in an HTML page, the corresponding <a> tag points to an address on the World Wide Web.

A Uniform Resource Locator (URL) is used to locate documents on the World Wide Web.

An example of a web page address: Grammar rules:

scheme :// host.domain : port / path / filename


  • scheme – defines the type of Internet service. The most common type is http
  • host – defines the domain host (the default host for http is www)
  • domain – defines the Internet domain name, such as
  • :port – defines the port number on the host (default port number for http is 80)
  • path – defines the path on the server (if omitted, the document must be in the root directory of the website).
  • filename – defines the name of the document/resource

Common URL Schemes

Here are some URL schemes:

httpHypertext Transfer ProtocolNormal web pages starting with http://. Not encrypted.
httpsSecure Hypertext Transfer ProtocolSecure web pages, encrypting all information exchanges.
ftpfile transfer protocolUsed to download or upload files to a website.
file files on your computer.

URL character encoding

URLs can only use the ASCII character set .

to send over the Internet. Since URLs often contain characters outside the ASCII set, URLs must be converted to a valid ASCII format.

URL encoding uses “%” followed by a two-digit hexadecimal number to replace non-ASCII characters.

The URL cannot contain spaces. URL encoding usually uses + to replace spaces.

URL Encoding Example

CharacterURL Editing

For a complete URL encoding reference, visit our URL Encoding Reference Manual .