What is Base64?

Base64 turns arbitrary data into a string of letters, digits and plus and slash signs — the format behind data URLs, HTTP basic auth headers, JWT payload segments and countless API fields that demand ASCII-safe text. This tool encodes plain text to Base64 and decodes Base64 back to text, both directions from the same input box.

The common gotcha it handles for you: Unicode. Naive Base64 implementations choke on anything beyond ASCII, but this tool encodes as UTF-8 first, so emoji, accented characters and CJK text survive a round trip intact. Decode a JWT's payload segment, inspect what a data URL actually contains, or produce a token for a system that wants credentials Base64-wrapped — paste, and the conversion is immediate.

Keep the purpose in mind: Base64 is an encoding, not encryption. Anyone can decode it instantly, so never treat it as a way to protect passwords or secrets; it exists to move binary data through channels that only tolerate text.

Everything runs locally in your browser — the text is processed by your own tab and never sent to a server, so it is fine to experiment with tokens, session data or API responses you would not paste into an unknown website.