Base64 maps binary data to an ASCII alphabet so it can travel through systems that expect text. Email attachments, basic auth headers, and many token formats rely on it.
Encoding ≠ encryption
Anyone can decode Base64. If you need confidentiality, use real encryption and proper key management — not encoding.
Base64URL and JWTs
JWTs use Base64URL (URL-safe alphabet, minimal padding). Decode tokens with the JWT Decoder or experiment with raw strings in the Base64 tool.