What is Base64?
Base64 turns any bytes into plain text using 64 safe characters (A–Z, a–z, 0–9, + and /). It is used to put binary data inside JSON, email, data URLs and HTTP headers such as Basic Auth. Base64 is an encoding, not encryption — anyone can decode it.
What is URL-safe Base64?
Standard Base64 uses + and /, which have special meaning in URLs. The URL-safe variant (base64url) replaces them with - and _ and usually drops the = padding. JWTs use base64url.
Does it handle emoji and non-English text?
Yes. Text is converted to UTF-8 bytes before encoding, so emoji, Tamil, Arabic, Chinese and every other script round-trip correctly.