The URL decoding functions support reversing of URL encoding operations to recreate the original data from the contents of a URL component.
Main two usages:
URL query: Refer the link data with space passed (marked in underline green) as
Form data: For the default content-type 'application/x-www-form-urlencoded'. The encoded form data is decoded as follows:
Control names and values are removed with escaped chars. '+' characters are replaced by spaces, and then reserved characters are restored that was escaped as described in [RFC1738], section 2.2: Non-alphanumeric characters and line breaks are restored back.
The encoded form data canca be a view in decoded via browser's 'Developer tools' > 'Network' tab > the respective URL's headers. Refer -
Developer Tool-kit is a set of online developer tools that help get the results of various functionality on-the-fly and diagnose.
Note - Since none of the user information does get stored on server, it is safe to use these tools