1var string = "Hello folks how are you doing today?";
2var encodedString = btoa(string); // Base64 encode the String
3var decodedString = atob(encodedString); // Base64 decode the String
4

1// Define the string
2var string = 'Hello World!';
3
4// Encode the String
5var encodedString = btoa(string);
6console.log(encodedString); // Outputs: "SGVsbG8gV29ybGQh"
7
8// Decode the String
9var decodedString = atob(encodedString);
10console.log(decodedString); // Outputs: "Hello World!"
11

1var decodedString = atob(encodedString);

1var decode = function(input) {
2        // Replace non-url compatible chars with base64 standard chars
3        input = input
4            .replace(/-/g, '+')
5            .replace(/_/g, '/');
6
7        // Pad out with standard base64 required padding characters
8        var pad = input.length % 4;
9        if(pad) {
10          if(pad === 1) {
11            throw new Error('InvalidLengthError: Input base64url string is the wrong length to determine padding');
12          }
13          input += new Array(5-pad).join('=');
14        }
15
16        return input;
17    }
18