Base64 Is Not Encryption: What Every Developer Gets Wrong

I once reviewed a codebase where API keys were "secured" by encoding them in Base64 before storing them in a config file. The developer genuinely believed this was a form of encryption. It is not. Base64 is an encoding scheme, not a cipher. Anyone can decode it instantly. Understanding what Base64 actually does, and what it does not do, will save you from shipping something embarrassing. What Base64 actually is Base64 converts binary data into a string of ASCII characters. That is the entire purpose. It exists because many systems -- email protocols, JSON payloads, HTML data URIs, URL parameters -- were designed to handle text, not arbitrary binary data. If you try to shove raw binary through a text-based protocol, certain bytes get misinterpreted as control characters, nulls get truncated, and data gets corrupted. Base64 solves this by mapping every 6 bits of input to one of 64 printable ASCII characters: A-Z, a-z, 0-9, +, and /. Three bytes of input (24 bits) become four Base64 chara