Base64 decoder and encoder online

Base64 is an worldwide standard encoding to represent binary data in an ASCII string. Each Base64 character represents exactly 6 bits of data. Therefore, four Base64 characters represent three bytes of data. A set of 64 characters are used and they vary slightly between different Base64 formats/implementations.

Decode or encode Base64 format

Note that you can type in either the Base64 or plaintext area.



  • The Base64 encoding can represent any binary data, although in many cases is represents text.
  • A total of 64 characters are used + a padding character. Commonly, = is used as padding character.
  • Usually, Base64 disregards of any whitespace characters in the Base64 code.
  • Wikipedia has a summary of variants of Base64.

Base64 encoding is frequently used in geocaching mystery caches, CTFs and logic puzzles. It can often be recognized by the padding characters (one or two =) at the end.

Sample text


The text above represents the word "ENCODING" encoded using base64 RFC 4648 (standard) format.