JWT Debugger

Decode JWT tokens and inspect header, payload, and signature.

JWT Token

Decoded Output

Header


                    
Payload

                    

                    
Signature

                    

                

            

            

                
About JWT (JSON Web Tokens)

                
                
What is JWT?

                
A JSON Web Token (JWT) is a compact, URL-safe means of representing claims to be transferred between two parties. JWTs are self-contained, meaning they carry all necessary information about the user or entity within the token itself. Defined in RFC 7519, JWTs have become the standard for stateless authentication and authorization in modern web applications and APIs.

                
                
JWT Structure

                
    
                  
  • Header: Contains the token type and the signing algorithm (e.g., HS256, RS256)
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  • Payload: Contains claims (user ID, roles, permissions, expiration time, etc.)
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  • Signature: Created by signing the header and payload to verify the token's integrity and authenticity
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Real-World Use Cases

                
    
                  
  • API Authentication: Secure REST APIs with token-based authentication instead of sessions
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  • Single Sign-On (SSO): Implement cross-domain or cross-application authentication
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  • Mobile Apps: Provide stateless authentication for iOS and Android applications
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  • Microservices: Enable secure communication between independent services
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  • Email Verification: Generate time-limited tokens for password resets and email confirmations
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  • Authorization: Encode user roles and permissions within the token for fine-grained access control
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