Format: Data URL (Base64-Encoded)

const convertBitArrtoB64 = (bitArr) => ( btoa( bitArr.reduce((data, byte) => data + String.fromCharCode(byte), '') ) );
const convertB64ToBitArr = (b64Str) => ( Uint8Array.from(atob( (b64Str.includes(';base64,') ? (b64Str.split(','))[1] : b64Str) ), (v) => v.charCodeAt(0)) );

const bitArr = (utf8Str) => (new TextEncoder().encode(utf8Str));
const utf8Str = (bitArr) => (new TextDecoder().decode(bitArr.buffer));

const utf8_to_b64 = ( str ) => ( btoa(unescape(encodeURIComponent( str ))) );
const b64_to_utf8 = ( str ) => ( decodeURIComponent(escape(atob( str ))) );