Mastering Modern Web Penetration Testing

URL encoding – percent encoding

In this section, I'll explain percent encoding, which is a commonly used encoding technique to encode URLs.

URL encoding is a way in which certain characters are encoded or substituted by % followed by the hexadecimal equivalent of the character. Developers often use encoding because there are certain cases when an intended character or representation is sent to the server but when received, the character changes or gets misinterpreted because of transport issues. Certain protocols such as OAuth also require some of its parameters, such as redirect_uri, to be percent encoded to make it distinct from rest of the URL for the browser.

Example: < is represented as %3c in percent encoding format.

URL encoding is done typically ...