If characters such as blanks and punctuation are passed in an HTTP stream, they might be misinterpreted at the receiving end. URL encoding converts characters that are not allowed in a URL into character-entity equivalents; URL decoding reverses the encoding. For example, when embedded in a block of text to be transmitted in a URL, the characters < and > are encoded as %3c and %3e.

To encode or decode values outside of a web application, use the System.Net.WebUtility class.

Namespace: System.Web
Assembly: System.Web (in System.Web.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0