base64 encoding

url in http can only be an ascii character. It means that it is not easy to put Hangul etc. For that reason, when passing parameters, it is delivered by url encoding.

Base64 encodes based on ascii. This means that the result is in ascii characters, so http uses it a lot. Of course? The same character is specially used in url, so even if you encode it as base64, url code must be done.