JWT decoder

In modern web and mobile applications secure communication often relies on tokens called JSON Web Tokens, or JWTs. A JWT contains encoded data that represents claims such as user identity, roles, or session information. When you need to inspect a token, troubleshoot authentication flows, or verify payload claims the JWT Decoder tool from SmartMeta makes the process fast and transparent.

By pasting a JWT into the tool you can instantly view the token header, the payload, and the signature component. This helps developers, security professionals, and system administrators understand what information is inside the token and whether it is valid or has been manipulated. The tool works in your browser and no token data is sent to external servers so your data stays private.

A JSON Web Token (JWT) is a compact, URL-safe token standard defined in RFC 7519. It is often used to transmit information securely between a client and a server. A JWT typically consists of three parts separated by dots: the header, payload, and signature. {CITATION_START}cite{CITATION_DELIMITER}turn0search0{CITATION_DELIMITER}CITATION_END

When a JWT is issued your server may sign it using a secret key or private key and the recipient verifies it. Decoding the token reveals the content of the header and payload but it does not verify the signature by itself.

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• Instant Extraction: Paste a JWT and view the header, payload, and signature instantly.
• Safe and Private: All decoding happens locally in your browser; nothing is uploaded.
• Troubleshooting Made Simple :Quickly inspect token contents when debugging login flows, API access errors or session issues.
• Learning and Documentation :Developers new to JWT can use this tool to understand how tokens are structured and how claims are stored.
• Supports All JWT Formats: Whether you have HS256, RS256 or other algorithm tokens this tool handles them for decoding.

• How to Use the JWT Decoder Tool

• Paste the token into the input field of the JWT Decoder.

• Click Decode Token to see the header, payload, and signature separated and formatted.

• Review the payload claims such as iss, sub, aud, exp, and custom claims per your application.

• For security reasons always verify the token signature and expiration on your server side. Decoding alone does not guarantee authenticity. {CITATION_START}cite{CITATION_DELIMITER}turn0search1{CITATION_DELIMITER}CITATION_END

• API and Microservice Debugging:Inspect tokens used for authentication in distributed systems.
• Client Side Validation: Understand what claims are carried by a token before trusting it.
• Security Audits: Check for sensitive data exposure in JWT payloads.
• Learning and Documentation: Demonstrate token structure to team members or trainees.