Base64 Encoder & Decoder
Encode text to Base64 or decode it back. Full Unicode support, plus URL-safe output for tokens and query strings.
Runs entirely in your browser — nothing you paste is uploaded or stored.
About base64 encode / decode
Base64 turns arbitrary bytes into plain ASCII so they can travel through things that only accept text — a JSON field, an HTTP header, a data URI, an email attachment.
It is an encoding, not encryption. Anything Base64-encoded can be decoded by anyone, instantly, with no key. It hides nothing; it only makes bytes safe to transport.
Good to know
- Unicode is handled properly. Many Base64 tools call the browser's btoa() directly, which throws on any character outside Latin-1 — so an emoji or an accented letter fails. This encodes UTF-8 bytes first, so any text works.
- URL-safe mode swaps + and / for - and _ and drops the padding, which is the variant used in JWTs and in URL query parameters.
- Decoding tolerates missing padding and whitespace, since Base64 copied out of a log or a header often arrives wrapped or truncated at the end.