Percent-encoding

Percent-encoding is a mechanism to encode 8-bit characters that have specific meaning in the context of URLs. It is sometimes called URL encoding. The encoding consists of substitution: A ’%’ followed by the hexadecimal representation of the ASCII value of the replace character.

Special characters needing encoding are: ’:’, ’/’, ’?’, ’#’, ’[’, ’]’, ’@’, ’!’, ’$’, ’&’, ”’”, ’(’, ’)’, ’*’, ’+’, ’,’, ’;’, ’=’, as well as ’%’ itself. Other characters don’t need to be encoded, though they could.

Character Encoding ’:’ %3A ’/’ %2F ’?’ %3F ’#’ %23 ’[’ %5B ’]’ %5D ’@’ %40 ’!’ %21 ’$’ %24 ’&’ %26 ”’” %27 ’(’ %28 ’)’ %29 ’*’ %2A ’+’ %2B ’,’ %2C ’;’ %3B ’=’ %3D ’%’ %25 ’ ’ %20 or +

Depending on the context, the character ’ ’ is translated to a ’+’ (like in the percent-encoding version used in an application/x-www-form-urlencoded message), or in ‘%20’ like on URLs.