What Base64 is
Base64 is an encoding scheme that turns binary data, or any text, into a sequence of safe characters for transmission through systems that only handle plain text well, such as email, JSON and URLs. It uses a set of 64 characters, uppercase and lowercase letters, digits, plus "+" and "/", to represent the original data, and uses "=" at the end as padding when needed.
Base64 is not encryption
A common mistake is thinking that encoding something in Base64 protects the information. It does not: Base64 is just a different representation of the same data, and anyone can decode it back to the original value without needing a password, key or any secret. Never use Base64 alone to protect passwords, tokens or sensitive data; use real encryption for that.
Where Base64 shows up in everyday use
Base64 appears often in several technical contexts: embedding images directly in HTML or CSS code without a separate file, transmitting binary data inside JSON, which only accepts text, encoding credentials in HTTP Basic authentication headers, and representing tokens in systems like JWT (JSON Web Token).
Support for accented characters and emoji (UTF-8)
Original Base64 was designed for simple bytes, which causes problems when encoding accented characters or emoji directly without proper handling. This tool converts the text to UTF-8 before encoding, and reverses the process when decoding, making sure accents and emoji round-trip correctly.
URL-safe Base64
Standard Base64 uses the characters "+", "/" and "=", which have special meaning inside a URL and can cause errors if used without proper handling. The URL-safe variation replaces "+" with "-", "/" with "_", and removes the trailing "=" padding, making the value safe to use directly as part of a link or URL parameter.