You can either enter a URI or certain characters that you want to
Encode or
Decode. The values
are encoded in their hex values. Decoding does the oposite.
For example, if you enter a ? and hit
Encode, you will
see %3F as the result.
Also note that escaping is a bit different if you enter a valid URI (meaning it begins with a scheme, continues with the authority part (e.g. user:password and/or domain name), etc. If it's a valid URI, only the authority, the query string, and fragment name will be encoded.