This will encode or decode base64, urlencode, rot13 or htmlentities to its counterpart.

Base64 decode encode

Base64 is a byte sequence of 8-bit padded ascii in mime.

More: Wikipedia and RFC 2045

URLencode decode encode

Tyically used for passing strings and variables between web pages

More info: and RFC 3986

ROT13 encode

Rotates the characters 13 places. Since the basic latin1 alphabet has 26 characters, performing rot13 on a string encrypts it. Do it twice, and it's decrypted.

More info: Wikipedia and

HTMLentities decode encode

Encodes or decodes all characters that have a HTML equivalent entity.

More info: and