Is an empty string valid base64 encoded data of zero bytes length?

Question

One of my colleges was telling me that the empty string is not a valid base64 encoded data string. I don\'t think this is true (he is too lazy to parse it), but after googling a

Answer 1

According to RFC 4648 Section 10, Test Vectors,

BASE64("") = ""

I would assume the inverse must hold as well.