function mepr_base64_decode(encodedData) { var decodeUTF8string = function(str) { // Going backwards: from bytestream, to percent-encoding, to original string. return decodeURIComponent(str.split('').map( function(c) { return '%' + ('00' + c.charCodeAt(0).toString(16)).slice(-2) }) .join('') ) } if (typeof window !== 'undefined') { if (typeof window.atob !== 'undefined') { return decodeUTF8string(window.atob(encodedData)) } } else { return new Buffer(encodedData, 'base64').toString('utf-8') } var b64 = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=' var o1 var o2 var o3 var h1 var h2 var h3 var h4 var bits var i = 0 var ac = 0 var dec = '' var tmpArr = [] if (!encodedData) { return encodedData } encodedData += '' do { // unpack four hexets into three octets using index points in b64 h1 = b64.indexOf(encodedData.charAt(i++)) h2 = b64.indexOf(encodedData.charAt(i++)) h3 = b64.indexOf(encodedData.charAt(i++)) h4 = b64.indexOf(encodedData.charAt(i++)) bits = h1 << 18 | h2 << 12 | h3 <> 16 & 0xff o2 = bits >> 8 & 0xff o3 = bits & 0xff if (h3 === 64) { tmpArr[ac++] = String.fromCharCode(o1) } else if (h4 === 64) { tmpArr[ac++] = String.fromCharCode(o1, o2) } else { tmpArr[ac++] = String.fromCharCode(o1, o2, o3) } } while (i < encodedData.length) dec = tmpArr.join('') return decodeUTF8string(dec.replace(/\0+$/, '')) } jQuery(document).ready(function() { var el = document.getElementById("mepr_math_captcha-6979d923b87d7") el.innerHTML = mepr_base64_decode("OSArIDUgZXF1YWxzPw=="); });