The URL encoding functions focus on taking program data and making it safe for use as URL components by quoting special characters and appropriately encoding non-ASCII text.
Main two usages:
URL query: Refer URL data pass as query string as
Form data: For the default content type 'application/x-www-form-urlencoded'. The Forms submitted with this content type must be encoded as follows:
Control names and values are escaped. Space characters are replaced by '+', and then reserved characters are escaped as described in [RFC1738], section 2.2: Non-alphanumeric characters are replaced by `%HH', a percent sign and two hexadecimal digits representing the ASCII code of the character. Line breaks are represented as "CR LF" pairs (i.e., `%0D%0A').
The control names/values are listed in the order they appear in the document. The name is separated from the value by '=' and name/value pairs are separated from each other by '&'.
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