jsonwebtoken vs jwt-simple

JWT Handling in JavaScript Applications

jsonwebtoken and jwt-simple are both npm packages designed to work with JSON Web Tokens (JWTs) in JavaScript environments. They provide utilities for signing, verifying, and decoding JWTs according to the RFC 7519 standard. jsonwebtoken is a full-featured, widely adopted library that supports advanced options like audience/issuer validation, clock tolerance, and algorithm restrictions. jwt-simple, by contrast, offers a minimal, low-level API focused strictly on encoding and decoding tokens without built-in verification safeguards or high-level abstractions.

Package	Downloads	Stars	Size	Issues	Publish	License

jsonwebtoken	26,689,061	18,109	43.5 kB	185	2 years ago	MIT
jwt-simple	290,072	1,359	-	34	7 years ago	MIT

jwtwebtoken vs jwt-simple: Security, Features, and Maintenance Compared

Both jsonwebtoken and jwt-simple let you work with JSON Web Tokens (JWTs) in JavaScript, but they serve very different needs. One is a full-featured, production-grade toolkit; the other is a barebones utility with minimal safety rails. Let’s compare them head-to-head.

🔐 Token Verification: Built-In Safety vs DIY Validation

jsonwebtoken includes comprehensive, standards-compliant verification out of the box.

Automatically checks exp (expiration), nbf (not before), and iat (issued at) claims.
Supports aud (audience), iss (issuer), and sub (subject) validation.
Handles clock skew via the clockTolerance option.

// jsonwebtoken: Full verification
const jwt = require('jsonwebtoken');

const payload = { sub: '123', exp: Math.floor(Date.now() / 1000) + 60 };
const token = jwt.sign(payload, 'secret');

try {
  const decoded = jwt.verify(token, 'secret', {
    audience: 'my-app',
    issuer: 'auth-server',
    clockTolerance: 10 // seconds
  });
  console.log(decoded);
} catch (err) {
  // Invalid, expired, or tampered token
}

jwt-simple only decodes tokens — it does not verify signatures or claims.

You must manually check expiration, issuer, audience, etc.
No protection against replay attacks or clock drift.

// jwt-simple: Manual everything
const jwt = require('jwt-simple');

const payload = { sub: '123', exp: Math.floor(Date.now() / 1000) + 60 };
const token = jwt.encode(payload, 'secret');

// Decode without signature verification!
const decoded = jwt.decode(token, 'secret');

// You must check exp yourself
if (decoded.exp < Date.now() / 1000) {
  throw new Error('Token expired');
}

⚠️ Critical note: jwt-simple's decode() method does not validate the signature by default unless you pass the secret. Even then, it won’t check standard claims like exp. This makes it easy to accidentally accept forged or expired tokens.

🧪 Algorithm Support and Security

jsonwebtoken enforces secure defaults and guards against common pitfalls.

Explicitly requires specifying allowed algorithms during verification.
Prevents algorithm confusion attacks (e.g., accepting none when expecting HS256).
Supports RSA, ECDSA, and HMAC algorithms.

// jsonwebtoken: Safe algorithm handling
jwt.verify(token, publicKey, {
  algorithms: ['RS256'] // Only allow RS256
});

jwt-simple accepts any algorithm and provides no safeguards.

Passing { algorithm: 'none' } during encode creates unsigned tokens.
No way to restrict algorithms during decode — you’re on your own.

// jwt-simple: Risky by default
const unsigned = jwt.encode({ foo: 'bar' }, null, 'none');
// Anyone can forge this token

📦 API Design and Developer Experience

jsonwebtoken uses separate methods for each operation:

sign() for creating tokens
verify() for safe validation
decode() (without verification) only when explicitly needed

This separation makes intent clear and reduces accidental misuse.

// Clear separation of concerns
const token = jwt.sign(payload, secret);
const verified = jwt.verify(token, secret);
const raw = jwt.decode(token); // No verification

jwt-simple uses just two methods:

encode() for signing
decode() for parsing (with optional secret)

But because decode() doesn’t enforce claim validation, developers often assume a decoded token is “valid” when it’s not.

🛠️ Maintenance and Trustworthiness

As of 2024, jsonwebtoken is actively maintained, receives regular security patches, and is used by thousands of production systems. It follows responsible disclosure practices and addresses vulnerabilities promptly.

jwt-simple, however, has seen no meaningful updates since 2018. Its GitHub repository shows no recent activity, and the package lacks modern security hardening. While not officially deprecated on npm, its stagnation makes it a risky choice for new projects.

🆚 Summary: Key Differences

Feature	`jsonwebtoken`	`jwt-simple`
Signature Verification	✅ Built into `verify()`	❌ Manual (easy to skip)
Claim Validation	✅ `exp`, `nbf`, `aud`, `iss`, etc.	❌ Must implement yourself
Algorithm Safety	✅ Enforces allowed algorithms	❌ Accepts any algorithm
Clock Tolerance	✅ Configurable	❌ None
Maintenance Status	✅ Actively maintained	❌ Inactive since ~2018
Use Case Fit	Production apps, APIs, auth systems	Legacy code, non-security contexts

💡 Final Recommendation

For any application handling authentication or authorization, use jsonwebtoken. Its built-in protections prevent entire classes of security bugs that are easy to introduce with lower-level tools.

Avoid jwt-simple in new projects — especially on the server side. If you’re already using it, audit your code for missing expiration checks, unsigned token acceptance, and algorithm validation gaps. In rare cases where bundle size is critical (e.g., embedded frontend widgets that only display tokens), consider whether you even need a library — sometimes atob() and JSON parsing suffice for read-only scenarios.

Remember: JWTs aren’t just data containers — they’re security credentials. Treat them accordingly.

jsonwebtoken:
Choose jsonwebtoken if you need a production-ready, secure, and well-maintained JWT implementation with robust verification features like audience/issuer checks, expiration handling with clock skew tolerance, and support for multiple cryptographic algorithms. It’s the de facto standard for Node.js applications requiring compliant JWT handling and is actively maintained with regular security updates.
jwt-simple:
Choose jwt-simple only for extremely constrained environments where you require a tiny, dependency-free encoder/decoder and are prepared to implement all security validations (like expiration, issuer, audience) manually. Note that it lacks built-in token verification safeguards and has not seen active maintenance in recent years — avoid it for new server-side or security-sensitive projects.

jsonwebtoken

jwt-simple

jsonwebtoken

Build	Dependency

An implementation of JSON Web Tokens.

This was developed against draft-ietf-oauth-json-web-token-08. It makes use of node-jws

Install

$ npm install jsonwebtoken

Migration notes

Usage

jwt.sign(payload, secretOrPrivateKey, [options, callback])

(Asynchronous) If a callback is supplied, the callback is called with the err or the JWT.

(Synchronous) Returns the JsonWebToken as string

payload could be an object literal, buffer or string representing valid JSON.

Please note that exp or any other claim is only set if the payload is an object literal. Buffer or string payloads are not checked for JSON validity.

If payload is not a buffer or a string, it will be coerced into a string using JSON.stringify.

secretOrPrivateKey is a string (utf-8 encoded), buffer, object, or KeyObject containing either the secret for HMAC algorithms or the PEM encoded private key for RSA and ECDSA. In case of a private key with passphrase an object { key, passphrase } can be used (based on crypto documentation), in this case be sure you pass the algorithm option. When signing with RSA algorithms the minimum modulus length is 2048 except when the allowInsecureKeySizes option is set to true. Private keys below this size will be rejected with an error.

options:

algorithm (default: HS256)
expiresIn: expressed in seconds or a string describing a time span vercel/ms.

Eg: 60, "2 days", "10h", "7d". A numeric value is interpreted as a seconds count. If you use a string be sure you provide the time units (days, hours, etc), otherwise milliseconds unit is used by default ("120" is equal to "120ms").
notBefore: expressed in seconds or a string describing a time span vercel/ms.

Eg: 60, "2 days", "10h", "7d". A numeric value is interpreted as a seconds count. If you use a string be sure you provide the time units (days, hours, etc), otherwise milliseconds unit is used by default ("120" is equal to "120ms").
audience
issuer
jwtid
subject
noTimestamp
header
keyid
mutatePayload: if true, the sign function will modify the payload object directly. This is useful if you need a raw reference to the payload after claims have been applied to it but before it has been encoded into a token.
allowInsecureKeySizes: if true allows private keys with a modulus below 2048 to be used for RSA
allowInvalidAsymmetricKeyTypes: if true, allows asymmetric keys which do not match the specified algorithm. This option is intended only for backwards compatability and should be avoided.

There are no default values for expiresIn, notBefore, audience, subject, issuer. These claims can also be provided in the payload directly with exp, nbf, aud, sub and iss respectively, but you can't include in both places.

Remember that exp, nbf and iat are NumericDate, see related Token Expiration (exp claim)

The header can be customized via the options.header object.

Generated jwts will include an iat (issued at) claim by default unless noTimestamp is specified. If iat is inserted in the payload, it will be used instead of the real timestamp for calculating other things like exp given a timespan in options.expiresIn.

Synchronous Sign with default (HMAC SHA256)

var jwt = require('jsonwebtoken');
var token = jwt.sign({ foo: 'bar' }, 'shhhhh');

Synchronous Sign with RSA SHA256

// sign with RSA SHA256
var privateKey = fs.readFileSync('private.key');
var token = jwt.sign({ foo: 'bar' }, privateKey, { algorithm: 'RS256' });

Sign asynchronously

jwt.sign({ foo: 'bar' }, privateKey, { algorithm: 'RS256' }, function(err, token) {
  console.log(token);
});

Backdate a jwt 30 seconds

var older_token = jwt.sign({ foo: 'bar', iat: Math.floor(Date.now() / 1000) - 30 }, 'shhhhh');

Token Expiration (exp claim)

The standard for JWT defines an exp claim for expiration. The expiration is represented as a NumericDate:

A JSON numeric value representing the number of seconds from 1970-01-01T00:00:00Z UTC until the specified UTC date/time, ignoring leap seconds. This is equivalent to the IEEE Std 1003.1, 2013 Edition [POSIX.1] definition "Seconds Since the Epoch", in which each day is accounted for by exactly 86400 seconds, other than that non-integer values can be represented. See RFC 3339 [RFC3339] for details regarding date/times in general and UTC in particular.

This means that the exp field should contain the number of seconds since the epoch.

Signing a token with 1 hour of expiration:

jwt.sign({
  exp: Math.floor(Date.now() / 1000) + (60 * 60),
  data: 'foobar'
}, 'secret');

Another way to generate a token like this with this library is:

jwt.sign({
  data: 'foobar'
}, 'secret', { expiresIn: 60 * 60 });

//or even better:

jwt.sign({
  data: 'foobar'
}, 'secret', { expiresIn: '1h' });

jwt.verify(token, secretOrPublicKey, [options, callback])

(Asynchronous) If a callback is supplied, function acts asynchronously. The callback is called with the decoded payload if the signature is valid and optional expiration, audience, or issuer are valid. If not, it will be called with the error.

(Synchronous) If a callback is not supplied, function acts synchronously. Returns the payload decoded if the signature is valid and optional expiration, audience, or issuer are valid. If not, it will throw the error.

Warning: When the token comes from an untrusted source (e.g. user input or external requests), the returned decoded payload should be treated like any other user input; please make sure to sanitize and only work with properties that are expected

token is the JsonWebToken string

secretOrPublicKey is a string (utf-8 encoded), buffer, or KeyObject containing either the secret for HMAC algorithms, or the PEM encoded public key for RSA and ECDSA. If jwt.verify is called asynchronous, secretOrPublicKey can be a function that should fetch the secret or public key. See below for a detailed example

As mentioned in this comment, there are other libraries that expect base64 encoded secrets (random bytes encoded using base64), if that is your case you can pass Buffer.from(secret, 'base64'), by doing this the secret will be decoded using base64 and the token verification will use the original random bytes.

options

algorithms: List of strings with the names of the allowed algorithms. For instance, ["HS256", "HS384"].
If not specified a defaults will be used based on the type of key provided
- secret - ['HS256', 'HS384', 'HS512']
- rsa - ['RS256', 'RS384', 'RS512']
- ec - ['ES256', 'ES384', 'ES512']
- default - ['RS256', 'RS384', 'RS512']
audience: if you want to check audience (aud), provide a value here. The audience can be checked against a string, a regular expression or a list of strings and/or regular expressions.

Eg: "urn:foo", /urn:f[o]{2}/, [/urn:f[o]{2}/, "urn:bar"]
complete: return an object with the decoded { payload, header, signature } instead of only the usual content of the payload.
issuer (optional): string or array of strings of valid values for the iss field.
jwtid (optional): if you want to check JWT ID (jti), provide a string value here.
ignoreExpiration: if true do not validate the expiration of the token.
ignoreNotBefore...
subject: if you want to check subject (sub), provide a value here
clockTolerance: number of seconds to tolerate when checking the nbf and exp claims, to deal with small clock differences among different servers
maxAge: the maximum allowed age for tokens to still be valid. It is expressed in seconds or a string describing a time span vercel/ms.

Eg: 1000, "2 days", "10h", "7d". A numeric value is interpreted as a seconds count. If you use a string be sure you provide the time units (days, hours, etc), otherwise milliseconds unit is used by default ("120" is equal to "120ms").
clockTimestamp: the time in seconds that should be used as the current time for all necessary comparisons.
nonce: if you want to check nonce claim, provide a string value here. It is used on Open ID for the ID Tokens. (Open ID implementation notes)
allowInvalidAsymmetricKeyTypes: if true, allows asymmetric keys which do not match the specified algorithm. This option is intended only for backwards compatability and should be avoided.

// verify a token symmetric - synchronous
var decoded = jwt.verify(token, 'shhhhh');
console.log(decoded.foo) // bar

// verify a token symmetric
jwt.verify(token, 'shhhhh', function(err, decoded) {
  console.log(decoded.foo) // bar
});

// invalid token - synchronous
try {
  var decoded = jwt.verify(token, 'wrong-secret');
} catch(err) {
  // err
}

// invalid token
jwt.verify(token, 'wrong-secret', function(err, decoded) {
  // err
  // decoded undefined
});

// verify a token asymmetric
var cert = fs.readFileSync('public.pem');  // get public key
jwt.verify(token, cert, function(err, decoded) {
  console.log(decoded.foo) // bar
});

// verify audience
var cert = fs.readFileSync('public.pem');  // get public key
jwt.verify(token, cert, { audience: 'urn:foo' }, function(err, decoded) {
  // if audience mismatch, err == invalid audience
});

// verify issuer
var cert = fs.readFileSync('public.pem');  // get public key
jwt.verify(token, cert, { audience: 'urn:foo', issuer: 'urn:issuer' }, function(err, decoded) {
  // if issuer mismatch, err == invalid issuer
});

// verify jwt id
var cert = fs.readFileSync('public.pem');  // get public key
jwt.verify(token, cert, { audience: 'urn:foo', issuer: 'urn:issuer', jwtid: 'jwtid' }, function(err, decoded) {
  // if jwt id mismatch, err == invalid jwt id
});

// verify subject
var cert = fs.readFileSync('public.pem');  // get public key
jwt.verify(token, cert, { audience: 'urn:foo', issuer: 'urn:issuer', jwtid: 'jwtid', subject: 'subject' }, function(err, decoded) {
  // if subject mismatch, err == invalid subject
});

// alg mismatch
var cert = fs.readFileSync('public.pem'); // get public key
jwt.verify(token, cert, { algorithms: ['RS256'] }, function (err, payload) {
  // if token alg != RS256,  err == invalid signature
});

// Verify using getKey callback
// Example uses https://github.com/auth0/node-jwks-rsa as a way to fetch the keys.
var jwksClient = require('jwks-rsa');
var client = jwksClient({
  jwksUri: 'https://sandrino.auth0.com/.well-known/jwks.json'
});
function getKey(header, callback){
  client.getSigningKey(header.kid, function(err, key) {
    var signingKey = key.publicKey || key.rsaPublicKey;
    callback(null, signingKey);
  });
}

jwt.verify(token, getKey, options, function(err, decoded) {
  console.log(decoded.foo) // bar
});

Need to peek into a JWT without verifying it? (Click to expand)

jwt.decode(token [, options])

(Synchronous) Returns the decoded payload without verifying if the signature is valid.

Warning: This will not verify whether the signature is valid. You should not use this for untrusted messages. You most likely want to use jwt.verify instead.

Warning: When the token comes from an untrusted source (e.g. user input or external request), the returned decoded payload should be treated like any other user input; please make sure to sanitize and only work with properties that are expected

token is the JsonWebToken string

options:

json: force JSON.parse on the payload even if the header doesn't contain "typ":"JWT".
complete: return an object with the decoded payload and header.

Example

// get the decoded payload ignoring signature, no secretOrPrivateKey needed
var decoded = jwt.decode(token);

// get the decoded payload and header
var decoded = jwt.decode(token, {complete: true});
console.log(decoded.header);
console.log(decoded.payload)

Errors & Codes

Possible thrown errors during verification. Error is the first argument of the verification callback.

TokenExpiredError

Thrown error if the token is expired.

Error object:

name: 'TokenExpiredError'
message: 'jwt expired'
expiredAt: [ExpDate]

jwt.verify(token, 'shhhhh', function(err, decoded) {
  if (err) {
    /*
      err = {
        name: 'TokenExpiredError',
        message: 'jwt expired',
        expiredAt: 1408621000
      }
    */
  }
});

JsonWebTokenError

Error object:

name: 'JsonWebTokenError'
message:
- 'invalid token' - the header or payload could not be parsed
- 'jwt malformed' - the token does not have three components (delimited by a .)
- 'jwt signature is required'
- 'invalid signature'
- 'jwt audience invalid. expected: [OPTIONS AUDIENCE]'
- 'jwt issuer invalid. expected: [OPTIONS ISSUER]'
- 'jwt id invalid. expected: [OPTIONS JWT ID]'
- 'jwt subject invalid. expected: [OPTIONS SUBJECT]'

jwt.verify(token, 'shhhhh', function(err, decoded) {
  if (err) {
    /*
      err = {
        name: 'JsonWebTokenError',
        message: 'jwt malformed'
      }
    */
  }
});

NotBeforeError

Thrown if current time is before the nbf claim.

Error object:

name: 'NotBeforeError'
message: 'jwt not active'
date: 2018-10-04T16:10:44.000Z

jwt.verify(token, 'shhhhh', function(err, decoded) {
  if (err) {
    /*
      err = {
        name: 'NotBeforeError',
        message: 'jwt not active',
        date: 2018-10-04T16:10:44.000Z
      }
    */
  }
});

Algorithms supported

Array of supported algorithms. The following algorithms are currently supported.

alg Parameter Value	Digital Signature or MAC Algorithm
HS256	HMAC using SHA-256 hash algorithm
HS384	HMAC using SHA-384 hash algorithm
HS512	HMAC using SHA-512 hash algorithm
RS256	RSASSA-PKCS1-v1_5 using SHA-256 hash algorithm
RS384	RSASSA-PKCS1-v1_5 using SHA-384 hash algorithm
RS512	RSASSA-PKCS1-v1_5 using SHA-512 hash algorithm
PS256	RSASSA-PSS using SHA-256 hash algorithm (only node ^6.12.0 OR >=8.0.0)
PS384	RSASSA-PSS using SHA-384 hash algorithm (only node ^6.12.0 OR >=8.0.0)
PS512	RSASSA-PSS using SHA-512 hash algorithm (only node ^6.12.0 OR >=8.0.0)
ES256	ECDSA using P-256 curve and SHA-256 hash algorithm
ES384	ECDSA using P-384 curve and SHA-384 hash algorithm
ES512	ECDSA using P-521 curve and SHA-512 hash algorithm
none	No digital signature or MAC value included

Refreshing JWTs

First of all, we recommend you to think carefully if auto-refreshing a JWT will not introduce any vulnerability in your system.

We are not comfortable including this as part of the library, however, you can take a look at this example to show how this could be accomplished. Apart from that example there are an issue and a pull request to get more knowledge about this topic.

TODO

X.509 certificate chain is not checked

Issue Reporting

If you have found a bug or if you have a feature request, please report them at this repository issues section. Please do not report security vulnerabilities on the public GitHub issue tracker. The Responsible Disclosure Program details the procedure for disclosing security issues.

Author

Auth0

License

This project is licensed under the MIT license. See the LICENSE file for more info.