如果你使用Node.JS 你可以通过以下方式使用本机Buffer模块:

const token = 'eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiYWRtaW4iOnRydWUsImp0aSI6ImU3YjQ0Mjc4LTZlZDYtNDJlZC05MTZmLWFjZDQzNzhkM2U0YSIsImlhdCI6MTU5NTg3NzUxOCwiZXhwIjoxNTk1ODgxMTE4fQ.WXyDlDMMSJAjOFF9oAU9JrRHg2wio-WolWAkAaY3kg4';
const tokenDecodablePart = token.split('.')[1];
const decoded = Buffer.from(tokenDecodablePart, 'base64').toString();
console.log(decoded)

你就可以开始了:-)

@Peheje将工作，但你将有问题的unicode。 为了解决这个问题，我使用https://stackoverflow.com/a/30106551/5277071上的代码;

let b64DecodeUnicode = str => decodeURIComponent( Array.prototype.map.call(atob(str), c => '%' + ('00' + c.charCodeAt(0).toString(16)).slice(-2) ).join('')) let parseJwt = token => JSON.parse( b64DecodeUnicode( token.split('.')[1].replace('-', '+').replace('_', '/') ) ) let form = document.getElementById("form") form.addEventListener("submit", (e) => { form.out.value = JSON.stringify( parseJwt(form.jwt.value) ) e.preventDefault(); }) textarea{width:300px; height:60px; display:block} <form id="form" action="parse"> <textarea name="jwt">eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkrDtGhuIETDs8OoIiwiYWRtaW4iOnRydWV9.469tBeJmYLERjlKi9u6gylb-2NsjHLC_6kZNdtoOGsA</textarea> <textarea name="out"></textarea> <input type="submit" value="parse" /> </form>

根据这里和这里的回答:

const dashRE = /-/g;
const lodashRE = /_/g;

module.exports = function jwtDecode(tokenStr) {
  const base64Url = tokenStr.split('.')[1];
  if (base64Url === undefined) return null;
  const base64 = base64Url.replace(dashRE, '+').replace(lodashRE, '/');
  const jsonStr = Buffer.from(base64, 'base64').toString();
  return JSON.parse(jsonStr);
};

你可以定义并使用这个函数:

jwtDecode = b => JSON.parse(Buffer.from(b.split('.')[1], 'base64').toString('binary'));

答案基于GitHub - auth0/jwt-decode。修改输入/输出，包括字符串分割和返回对象{header, payload, signature}，这样你就可以传递整个令牌。

var jwtDecode = function (jwt) {

        function b64DecodeUnicode(str) {
            return decodeURIComponent(atob(str).replace(/(.)/g, function (m, p) {
                var code = p.charCodeAt(0).toString(16).toUpperCase();
                if (code.length < 2) {
                    code = '0' + code;
                }
                return '%' + code;
            }));
        }

        function decode(str) {
            var output = str.replace(/-/g, "+").replace(/_/g, "/");
            switch (output.length % 4) {
                case 0:
                    break;
                case 2:
                    output += "==";
                    break;
                case 3:
                    output += "=";
                    break;
                default:
                    throw "Illegal base64url string!";
            }

            try {
                return b64DecodeUnicode(output);
            } catch (err) {
                return atob(output);
            }
        }

        var jwtArray = jwt.split('.');

        return {
            header: decode(jwtArray[0]),
            payload: decode(jwtArray[1]),
            signature: decode(jwtArray[2])
        };

    };

简单的功能与试接

const parseJwt = (token) => {
  try {
    return JSON.parse(atob(token.split('.')[1]));
  } catch (e) {
    return null;
  }
};

谢谢!