Productive ToolboxJWT Debugger
Decode and inspect JSON Web Tokens instantly with claim analysis and expiration detection
JWT Debugger
Decode and inspect JSON Web Tokens instantly. We do not collect or store what you enter.
✓ We do not collect or store your tokens
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About JWT Debugger
The JWT Debugger is a powerful online tool designed to help developers decode and inspect JSON Web Tokens instantly. Whether you're debugging authentication issues, testing OAuth implementations, or analyzing token claims, this tool provides instant insights into your JWT structure.
What is a JWT?
A JSON Web Token (JWT) is a compact, URL-safe means of representing claims to be transferred between two parties. It consists of three Base64URL-encoded parts separated by dots: header, payload, and signature.
Key Features
- Instant JWT token decoding
- Header and payload inspection
- Expiration time conversion and detection
- Claim analysis and highlighting
- Token status indicator (valid/expired)
- Copy decoded sections to clipboard
- Base64URL visualization
- JSON syntax highlighting
- Local history tracking
- Private: your inputs are not collected or stored
How to Use
- Paste your JWT token into the input area
- The tool automatically decodes and displays the header and payload
- View token analysis including expiration time and claims
- Copy any section to your clipboard
- Check token status (valid/expired)
JWT Structure
A JWT consists of three parts:
- Header: Contains token type and hashing algorithm
- Payload: Contains claims (user data, expiration, etc.)
- Signature: Ensures token integrity and authenticity
Common JWT Claims
- exp: Expiration time (Unix timestamp)
- iat: Issued at time (Unix timestamp)
- nbf: Not before time (Unix timestamp)
- iss: Issuer of the token
- aud: Audience (intended recipient)
- sub: Subject (user identifier)
- jti: JWT ID (unique identifier)
Use Cases
- API Developers: Debug authentication tokens
- Backend Engineers: Inspect token claims and expiration
- Security Testing: Analyze token structure and validity
- OAuth Implementation: Verify token format and claims
- Troubleshooting: Identify token-related issues
Privacy & Security
We do not collect or store what you enter. This ensures complete privacy and security for sensitive authentication tokens.
Tips for Best Results
- Use the example tokens to understand JWT structure
- Check the expiration time to verify token validity
- Review all claims to understand token permissions
- Use the history feature to track recently decoded tokens
- Copy decoded sections for documentation or debugging
Frequently Asked Questions
What is a JSON Web Token (JWT)?
A compact token made of three Base64URL parts separated by dots: a header (the signing algorithm), a payload (claims such as the user ID and expiry) and a signature. Apps use JWTs for logins and API access.
Does this tool verify the signature?
No. It decodes the header and payload so you can read them, which needs no key. Checking that a token is genuine requires the signing secret or public key and should be done on your server.
What do the exp, iat and nbf claims mean?
They are Unix timestamps in seconds: exp is when the token expires, iat when it was issued and nbf the time before which it must not be accepted. The debugger converts them to readable dates and flags an expired token.
Is it safe to paste a token here?
We do not collect or store what you enter. Still treat live tokens like passwords: anyone holding an unexpired token can use it, so prefer test tokens and never paste them into sites you do not trust.
Is a JWT encrypted?
A normal signed JWT (JWS) is only encoded, not encrypted: anyone can read the payload. Do not put secrets in it. Encrypted tokens (JWE) have five parts and cannot be read without the key.
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