Encoding first converts your text to UTF-8 bytes with the browser's TextEncoder, then prints each byte as eight binary digits (0 and 1). This means Chinese characters, emoji and any Unicode text produce correct, standard byte sequences — one character may become several bytes. You can add a space between bytes for readability or leave it as one continuous stream.
Decoding is forgiving: whitespace is stripped and the remaining 0/1 stream is read in groups of eight bits, then decoded as UTF-8. Invalid input — non-binary characters or a length that is not a multiple of eight — is reported instead of producing garbage. Everything runs locally in your browser — nothing is uploaded.