w
Documentation Core Tools Jwt Parser

Basic Usage

This guide will walk you through the fundamental steps of using the JWT Parser tool to analyze JSON Web Tokens.

Step 1: Access the Tool

Navigate to the JWT Parser tool from the main tools page or directly via the URL /jwt-parser.

Step 2: Input Your JWT Token

Method 1: Manual Input

  1. Click in the "JWT Token" text area
  2. Paste or type your JWT token
  3. The tool will automatically parse the token as you type

Method 2: Load Example

  1. Click the "Load Example" button
  2. A sample JWT token will be loaded automatically
  3. This is useful for testing and learning the tool's functionality

Step 3: Review Parsed Results

Once a valid JWT token is entered, you'll see three main sections:

Header Information

  • Algorithm: The signing algorithm used (e.g., HS256, RS256)
  • Type: Token type (typically "JWT")
  • Additional Claims: Any other header claims

Payload Data

  • Standard Claims: iss, sub, aud, exp, nbf, iat, jti
  • Custom Claims: Any application-specific data
  • Expiration: When the token expires (if specified)

Signature

  • Raw Signature: The base64url-encoded signature
  • Verification Note: Reminder that this tool doesn't validate signatures

Step 4: Use Additional Features

Copy Results

  1. Click the "Copy Result" button
  2. The parsed information will be copied to your clipboard
  3. Paste into your preferred text editor or documentation

Clear Content

  1. Click "Clear All" to remove all content
  2. Start fresh with a new token

View History

  • Previously parsed tokens appear in the history section
  • Click any history item to reload that token
  • Use "Clear History" to remove all stored tokens

Understanding the Output

Header Example

{
  "alg": "HS256",
  "typ": "JWT"
}

Payload Example

{
  "sub": "1234567890",
  "name": "John Doe",
  "iat": 1516239022,
  "exp": 1516242622
}

Common Claims Explained

  • sub (Subject): The subject of the token
  • iat (Issued At): When the token was issued
  • exp (Expiration): When the token expires
  • aud (Audience): Intended recipient of the token
  • iss (Issuer): Who issued the token

Error Handling

Invalid Format

If you enter an invalid JWT format, you'll see an error message:

  • "Invalid JWT format. JWT should have 3 parts separated by dots."

Parsing Errors

If the token can't be parsed, you'll see:

  • "Failed to parse JWT token"

Common Issues

  • Missing dots: JWT must have exactly 2 dots separating 3 parts
  • Invalid base64: Each part must be valid base64url encoding
  • Malformed JSON: Header and payload must be valid JSON

Best Practices

Security

  • Only use this tool with test tokens or tokens you own
  • Never share sensitive production tokens
  • Use in secure, private environments only

Development Workflow

  1. Generate test tokens in your development environment
  2. Parse them to verify structure and claims
  3. Use the results to debug authentication issues
  4. Clear history when switching between projects

Token Management

  • Keep a record of important test tokens
  • Use the history feature for frequently analyzed tokens
  • Clear history regularly to maintain privacy

Next Steps

Now that you understand the basics, explore Advanced Features to learn about more sophisticated usage patterns and Security Considerations for safe token handling.

Was this page helpful?