Base64 URL friendly

Encode / Decode a Base64 encoded String to a URL friendly format. That is, the '+' and '/' character are replaced by '-' and '_'. Also the padding '=' characters are removed.

by magikMaker

JavaScript

/**
 * use this to make a Base64 encoded string URL friendly, 
 * i.e. '+' and '/' are replaced with '-' and '_' also any trailing '=' 
 * characters are removed
 *
 * @param {String} str the encoded string
 * @returns {String} the URL friendly encoded String
 */
function Base64EncodeUrl(str){
    return str.replace(/\+/g, '-').replace(/\//g, '_').replace(/\=+$/, '');
}

/**
 * Use this to recreate a Base64 encoded string that was made URL friendly 
 * using Base64EncodeurlFriendly.
 * '-' and '_' are replaced with '+' and '/' and also it is padded with '+'
 *
 * @param {String} str the encoded string
 * @returns {String} the URL friendly encoded String
 */
function Base64DecodeUrl(str){
    str = (str + '===').slice(0, str.length + (str.length % 4));
    return str.replace(/-/g, '+').replace(/_/g, '/');
}

/**
 * Example:
 * This Base64 encoded string will be made URL friendly
 */
var encoded = 'VGhpcyBpcyBhbiBhd2Vzb21lIHNjcmlwdA==';

var url_encoded = Base64EncodeUrl(encoded);
var url_decoded = Base64DecodeUrl(url_encoded);

document.write(encoded + '<br />');
document.write(url_encoded + '<br />');
document.write(url_decoded + '<hr />');

// "Test"
document.write(url_decoded === encoded);