🔓 JWT Decoder

Decode JSON Web Tokens to inspect header and payload information

Version 2.1.0 - Updated September 2025
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Paste your JSON Web Token here. It should consist of three parts separated by dots (e.g., xxxxx.yyyyy.zzzzz).
Header:
Header will appear here
Payload:
Payload will appear here
Signature Verification:
Signature verification status will appear here

Embed This Tool

Want to embed this JWT decoder on your website? Use this code:

<iframe src="https://yoursite.com/jwt-decoder" width="100%" height="600" frameborder="0"></iframe>

🎯 Real-World JWT Examples

🌐 Authentication Token

Standard JWT used for user authentication in web applications.

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwidXNlcm5hbWUiOiJqb2huZG9lIiwicm9sZSI6InVzZXIiLCJpYXQiOjE1MTYyMzkwMjJ9.4Adcj3UFYzPUVaVF43FmMab6RlaQDEEaxC5McgFc

Contains: User ID, username, role, and issued at timestamp.

🔐 API Access Token

JWT used for accessing protected API endpoints.

eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwiYXBpX2FjY2VzcyI6dHJ1ZSwic2NvcGUiOiJyZWFkIHdyaXRlIiwiaWF0IjoxNTE2MjM5MDIyLCJleHAiOjE1MTY4NDM4MjJ9.KR4d4sx5jVl4L6c6z5q4Q4c4z5q4Q4c4z5q4Q4c4z5q4

Contains: API access permissions, scopes, and expiration time.

📧 Email Verification Token

JWT used for verifying user email addresses.

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VyX2lkIjoiMTIzNDU2Nzg5MCIsImVtYWlsIjoiam9obmRvZUBleGFtcGxlLmNvbSIsInR5cGUiOiJlbWFpbF92ZXJpZmljYXRpb24iLCJpYXQiOjE1MTYyMzkwMjJ9.1Lf4j3kF5lM9n8O7p6Q4r2S1t3V7w0X5y2Z4

Contains: User ID, email address, and token type.

🔄 Refresh Token

JWT used for obtaining new access tokens.

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwidHlwZSI6InJlZnJlc2giLCJpYXQiOjE1MTYyMzkwMjIsImV4cCI6MTUxODgzMTAyMn0.8Jf7k2L9m4N6b3V1c7X0z5Y8w2Q4r6T3p9

Contains: User ID, token type, and long expiration time.

📊 Analytics Token

JWT used for tracking user analytics while preserving privacy.

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VyX2lkIjoiMTIzNDU2Nzg5MCIsInNlc3Npb25faWQiOiJhYmNkZWYxMjM0NTY3ODkwIiwicGFnZV92aWV3cyI6NSwiZXZlbnRzIjpbImNsaWNrIiwic2Nyb2xsIl0sImlhdCI6MTUxNjIzOTAyMn0.3Kf6j2L8m5N7b4V2c8Y1z6X9w3R5s7U4q0

Contains: Anonymous user tracking data and events.

💳 Payment Token

JWT used for secure payment processing.

eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJwYXltZW50X2lkIjoiUE1UMTIzNDU2Nzg5MCIsImFtb3VudCI6MTAwLCJjdXJyZW5jeSI6IlVTRCIsInN0YXR1cyI6InBlbmRpbmciLCJpYXQiOjE1MTYyMzkwMjJ9.7Lg8k3M9n5O7b4V2c8Y1z6X9w3R5s7U4q0

Contains: Payment details, amount, currency, and status.

📚 JWT Tutorials & Guides

🔓

JWT Fundamentals: A Complete Guide

Learn the basics of JSON Web Tokens, how they work, and why they're essential for modern authentication.

Read Tutorial →
🌐

Implementing JWT Authentication

Step-by-step guide to implementing JWT authentication in web applications using various programming languages.

Read Tutorial →
🔐

JWT Security Best Practices

Learn how to securely implement JWT in your applications and avoid common security pitfalls.

Read Tutorial →

JWT vs Session Cookies: When to Use What

Compare JWT and traditional session-based authentication and learn when to use each approach.

Read Tutorial →
🛡️

Common JWT Security Mistakes

Learn about the most common security pitfalls when implementing JWT and how to avoid them.

Read Tutorial →
🔧

Testing JWT Implementations

Best practices for testing your JWT implementation, including validation and security testing.

Read Tutorial →

⚖️ JWT Tools Comparison

Compare our free JWT decoder with other popular tools and services:

Feature Our Tool Online Tool A Paid Service B Command Line
Free to Use
Client-side Processing
Pretty JSON Output
Copy Functionality
Embed Code
API Access ❌ (Client-side only) ✅ ($)
Mobile Friendly
Educational Content
Privacy (Client-side)

Why Choose Our JWT Decoder?

🔒 Complete Privacy

All decoding happens in your browser. Your JWT tokens never leave your device, ensuring maximum privacy and security.

🚀 Modern & Fast

Built with modern web standards and optimized for performance. Works instantly without server delays.

📱 Mobile Ready

Fully responsive design that works perfectly on all devices - desktop, tablet, and mobile.

🎓 Educational

Not just a tool - includes comprehensive guides, examples, and best practices to help you learn.

📝 Version History & Changelog

Version 2.1.0 - Latest

September 15, 2025
  • 🎉 Added signature verification status indicator
  • 📱 Improved mobile responsiveness and touch interactions
  • 🔧 Added embed code functionality for easy integration
  • 📊 Enhanced tooltips with detailed explanations
  • 🎨 Updated UI with better accessibility and contrast
  • ⚡ Optimized performance for faster JWT decoding

Version 2.0.0

August 20, 2025
  • 🔄 Complete UI redesign with modern styling
  • 📚 Added comprehensive tutorial section
  • 📝 Introduced tabbed navigation for better organization
  • ⚖️ Added tool comparison feature
  • 💾 Implemented copy functionality for results
  • 📋 Enhanced UI with better visual separation of JWT parts

Version 1.2.0

July 10, 2025
  • ✅ Added support for URL-safe base64 decoding
  • 🛡️ Improved error handling for malformed tokens
  • 📖 Added real-world examples and case studies
  • 🐛 Fixed UI rendering issues on mobile devices
  • ♿ Enhanced accessibility with ARIA labels

Version 1.1.0

June 5, 2025
  • 🎨 Improved visual design with gradient backgrounds
  • 📱 Added responsive design for mobile devices
  • ⚠️ Added warnings for expired tokens
  • 📋 Implemented one-click copy functionality
  • 🔧 Fixed JSON formatting issues

Version 1.0.0

May 15, 2025
  • 🎉 Initial release of JWT Decoder
  • 🔐 Support for decoding JWT header and payload
  • ⚡ Client-side processing for maximum privacy
  • 📚 Comprehensive documentation and examples
  • ✨ Clean, modern user interface

🔮 Upcoming Features

📋 Planned for Next Release:

  • JWT signature verification with public keys
  • Token expiration and validity checking
  • JWT creation/encoding functionality
  • Algorithm performance benchmarking
  • Dark/Light theme toggle
  • Keyboard shortcuts for power users
  • History of decoded tokens (session-based)

What is JWT?

JWT (JSON Web Token) is an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object. This information can be verified and trusted because it is digitally signed.

JWT Structure

A JWT consists of three parts separated by dots (.):

  1. Header: Typically consists of two parts - the type of token (JWT) and the signing algorithm being used.
  2. Payload: Contains the claims. Claims are statements about an entity (typically the user) and additional metadata.
  3. Signature: Used to verify that the sender of the JWT is who it says it is and to ensure that the message wasn't changed along the way.

🟢 When to Use JWT

✅ Appropriate Uses:

  • Authentication and authorization in web applications
  • Secure information exchange between parties
  • Stateless session management
  • API authentication and access control
  • Single Sign-On (SSO) functionality
  • Mobile application authentication

🔴 When Not to Use JWT

❌ Inappropriate Uses:

  • Storing sensitive data without encryption
  • As a replacement for server-side sessions when not needed
  • For very large payloads (JWT has size limitations)
  • When token revocation is frequently needed
  • As the sole security mechanism without additional protections

Security Features of JWT

🔒 Digital Signature

JWTs can be signed using a secret or a public/private key pair, ensuring the token hasn't been tampered with.

🛡️ Standardized Format

Follows RFC 7519 standard, ensuring interoperability across different systems and languages.

⚡ Compact Size

JWTs are compact and can be sent through URLs, POST parameters, or inside HTTP headers.

🔐 Self-contained

All required information is contained within the token itself, reducing database lookups.

Common JWT Claims

JWTs contain claims which are statements about an entity. Some registered claims include:

Security Best Practices

🔐 Recommended Security Resources

Enhance your security knowledge with these premium resources: