Remove trailing “=” when base64 encoding

Question

I am noticing that whenever I base64 encode a string, a \"=\" is appended at the end. Can I remove this character and then reliably decode it later by adding it back, or is

Answer 1

In JavaScript you could do something like this:

// if this is your Base64 encoded string
var str = 'VGhpcyBpcyBhbiBhd2Vzb21lIHNjcmlwdA=='; 

// make URL friendly:
str = str.replace(/\+/g, '-').replace(/\//g, '_').replace(/\=+$/, '');

// reverse to original encoding
if (str.length % 4 != 0){
  str += ('===').slice(0, 4 - (str.length % 4));
}
str = str.replace(/-/g, '+').replace(/_/g, '/');

See also this Fiddle: http://jsfiddle.net/7bjaT/66/