JWT Decoder

JWT Decoder

JWT Decoder

Use this tool to validate your JWT is being generated with the metadata and claims you expect, or check out the attributes of JWTs created by other systems.

To test the decoder, copy and paste the sample JWT below.


eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJDcmVkaXQiOiIyNTAwIiwiQ2FzaCI6IjUwMDAiLCJFbWFpbCI6WyJpbmZvQGlmbm8uY29tIl0sImV4cCI6MTcxNjQ0NzI2Mn0.W29iamVjdCBQcm9taXNlXQ

JWT Decoder

JWT Decoder

Header

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Payload

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JWT Decoder Tool User Guide

Step 1: Input JWT:

  1. Locate the text area labeled "Paste your JWT here...".
  2. Copy the JWT string that you want to decode.
  3. Paste the JWT string into the text area.

Step 2: Decode JWT:

  1. After pasting the JWT string, ensure that it appears correctly in the text area.
  2. Click on the "Decode JWT" button to initiate the decoding process.

Step 3: Viewing Decoded Information:

Upon clicking the "Decode JWT" button, the tool will attempt to decode the JWT.

  • If the decoding process is successful, the decoded header and payload will be displayed in separate sections below the input area.
  • The decoded information will be presented in a structured JSON format for easy readability.

Step 4: Copying Decoded Content:

To copy the decoded header or payload content, click on the 📋 icon next to the respective section. This will copy the content to your clipboard, allowing you to paste it into another document or application.

Step 5: Downloading Decoded Content:

To download the decoded content as a text file, click on the ⬇️ icon next to the respective section. This will prompt your browser to download the content as a file named "jwt_content.txt".

Step 6: Resetting the Tool:

To decode another JWT or start over, click on the "Try Again" button. This will clear the input area and reset the tool for a new decoding process.

Notes:

  • Ensure that the JWT string provided is valid and properly formatted.
  • If the provided JWT is invalid or cannot be decoded, an error message will be displayed.
  • The tool supports various algorithms used for encoding JWTs, providing flexibility in decoding different types of tokens.


JWT stands for JSON Web Token. It is a compact, URL-safe means of representing claims to be transferred between two parties. The claims in a JWT are encoded as a JSON object that is used as the payload of a JSON Web Signature (JWS) or encrypted using JSON Web Encryption (JWE).

JWTs are commonly used for authentication and authorization in web applications. They are often used as tokens for securely transmitting information between a client and a server. JWTs are structured into three main parts separated by dots:

Parts of a JWT:

  1. Header: Contains metadata about the type of token and the cryptographic algorithm used to secure the token.
  2. Payload: Contains the claims, which are statements about an entity (typically the user) and additional data. Claims are usually categorized as registered, public, or private claims.
  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.

JWTs are commonly used for authentication and authorization in web applications. They are often used as tokens for securely transmitting information between a client and a server.


Features of JWTs:

  • Self-contained: All the information needed for a client to understand and use the token is included in the token itself.
  • Stateless: The server does not need to store any session information about the user.

Overall, JWTs provide a lightweight and secure way to transmit information between parties, making them a popular choice for authentication and authorization in modern web applications.


Use Cases

  1. Debugging JWTs: Developers can use the tool to debug JWTs during the authentication process in web applications.
  2. Security Audits: Security professionals can use the tool to inspect JWTs for potential vulnerabilities and ensure they are securely encoded.
  3. Integration Testing: QA engineers can use the tool to verify JWTs generated by APIs during integration testing.
  4. Educational Purposes: Students and learners can use the tool to understand how JWTs are structured and encoded.

Benefits

  • Ease of Use: The tool provides a simple and intuitive interface for decoding JWTs, making it accessible to both developers and non-developers.
  • Instant Decoding: Users can quickly decode JWTs without the need for manual decoding or specialized software.
  • Visual Representation: The decoded JWT is presented in a structured JSON format, making it easy to understand and analyze.
  • Copy and Download: Users can easily copy or download the decoded content for further analysis or documentation.

Do's

  1. Verify JWT Validity: Always ensure that the JWT string provided is valid and properly formatted before decoding.
  2. Use Secure JWTs: Be cautious when decoding JWTs containing sensitive information and ensure they are securely transmitted and stored.
  3. Check for Errors: Verify that the decoding process completes successfully and review any error messages displayed by the tool.
  4. Keep JWTs Confidential: Avoid sharing decoded JWTs containing sensitive information with unauthorized parties.

Don'ts

  1. Modify Decoded Content: Do not modify the decoded content of JWTs as it may compromise their integrity or security.
  2. Share JWTs Unnecessarily: Avoid sharing decoded JWTs containing sensitive information in insecure channels or with unauthorized individuals.
  3. Rely Solely on Decoded JWTs: Do not solely rely on decoded JWTs for authentication or authorization decisions without proper validation.
  4. Decode Untrusted JWTs: Exercise caution when decoding JWTs obtained from untrusted or unknown sources to prevent security risks.