Base64 guides

What Is Base64?

Base64 is a binary-to-text encoding scheme. It represents three bytes as four printable characters so binary data can pass through systems designed for text, such as JSON, email, HTML, and URLs. The result is longer than the original data, but portable and predictable.

How the alphabet works

The standard alphabet contains A-Z, a-z, 0-9, plus, slash, and optional equals padding. Encoding is reversible: decoding recovers the original bytes exactly when the input is unchanged.

Encoding is not encryption

Anyone can decode Base64. Do not put passwords, private keys, or confidential records in Base64 and assume they are protected. Use TLS for transport and authenticated encryption when secrecy matters.

Try it yourself

Use the Base64 encoder and Base64 decoder, then read the complete guide.