This is Base64 decoding online tool. It supports standard RFC4648 Base64 encoding as well as url safe Base64 encoding and MIME RFC2045 Base64 encoding for multiple character encodings. Unlike most tools out there, this one is tolerable to invalid characters and therefore can be used to investigate binary base64 strings.
As Base64 is byte encoding, bytes must be decoded to string before display, usually using UTF-8. Additional character encodings supported are Hex, ASCII and Windows-1251.
Spaces are ignored, other non-base64 characters are used as delimiters. This is useful to decode JWT tokens for example.
Decoding errors are highlighted: yellow for non-base64 symbols, ? for symbols unrepresentable in current encoding, ! for unexpected end of base64 string.