Base64 Encoder / Decoder
Type in either box — the other updates instantly. Choose Standard (RFC 4648, uses+ / with = padding) or URL-safe (uses - _, no padding — the variant used in JWTs and URL query values).
Processed locally. Your text never leaves your browser.
Common questions
Is Base64 a form of encryption or security?
No — Base64 is purely a reversible text representation of binary data. Anyone can decode it back to the original with no key or password involved, so it provides zero confidentiality. Never use it to hide or protect sensitive data.
Does this support non-English text and emoji, not just ASCII?
Yes — text is encoded as UTF-8 bytes first, not with the older Latin1-only btoa() approach, which can't handle real Unicode and throws on many non-English characters or emoji.
What happens if I paste something that isn't valid Base64?
It's rejected with a specific error: an invalid character for the selected variant, a string length that can't be valid Base64, or — if the bytes decode but aren't valid UTF-8 text, such as pasting the Base64 of an image — a message saying so, rather than showing garbled replacement characters.