Getting Started

Introduction

Overview and basic concepts of JWT

Core Concepts

Validation & Verification

How to validate and verify JWT tokens

Payload & Structure

Understanding JWT payload and format

Support

Common Errors

Troubleshooting and error resolution

JWT Validation & Verification

Validation Process

JWT validation is a crucial security step that ensures the token is authentic, unaltered, and still valid. The validation process involves multiple checks that must all pass before accepting the token.

Signature Check

Verify the token's signature using the secret key to ensure it hasn't been tampered with.

Expiration Check

Check the token's expiration time (exp) to ensure it hasn't expired.

Claims Validation

Validate required claims like issuer (iss), audience (aud), and subject (sub).

Verification Steps

Signature Verification

How to verify the token's signature

// Node.js example using jsonwebtoken library
const jwt = require('jsonwebtoken');

try {
  const decoded = jwt.verify(token, secretKey, {
    algorithms: ['HS256'] // Specify allowed algorithms
  });
  // Token is valid
} catch (err) {
  // Token is invalid
  console.error('Token verification failed:', err.message);
}

Best Practices

Always implement all validation steps to ensure maximum security.

Recommended Practices

✓ Use strong, unique secret keys

✓ Implement proper error handling

✓ Validate all required claims

✓ Use appropriate token expiration times

✓ Implement token refresh mechanism

Implementation Checklist

Verify signature using correct algorithm

Check token expiration (exp claim)

Validate issuer and audience

Implement proper error handling

Developer Tools