Base64 turns binary or text into an alphabet of letters, digits, plus, slash and padding equals signs. You encode Base64 when a protocol wants safe ASCII — email attachments, data URLs, some API tokens. You decode Base64 when you need the original string back. This Base64 encoder and decoder runs locally. Nothing you paste is stored.
Encode versus decode
Encode takes plain text and produces Base64. Decode takes a Base64 string (whitespace is ignored) and restores UTF-8 text. If decode fails, the input was not valid Base64. Pair this with the URL encoder when a Base64 value also has to sit in a query string, or with the JSON formatter when a field inside JSON is Base64.
Privacy
Encoding is not hiding. For a random secret, use the password generator. More utilities live under online tools. If you came here from a slow connection, the speed test is separate.
Common questions
Is Base64 encryption?
No. Base64 is encoding, not encryption. Anyone can decode it. Do not put secrets in Base64 and call them hidden.
Does this Base64 encoder support Unicode?
Yes. Text is encoded as UTF-8 before Base64, so characters outside ASCII survive a round trip.