What is JWT Decoder?
JWT Decoder parses and decodes JSON Web Tokens (JWTs) without verification. It displays the header, payload, and signature in a readable format. JWTs are commonly used for authentication and authorization in web applications.
Common Use Cases
Debugging
Inspect JWT contents during development and debugging.
Token Analysis
View claims, expiration, and issuer information.
Security Review
Check what data is exposed in public JWT payloads.
Learning
Understand JWT structure and how they work.
How to Use This Tool
- Paste your JWT token
- View the decoded header and payload
- Check expiration and other claims
- Verify timestamps are in expected range
Frequently Asked Questions
Is JWT decoding secret?
No! JWT payloads are only Base64-encoded, not encrypted. Anyone can decode them. Never put sensitive data in JWTs.
Can this verify JWT signatures?
This tool decodes only. Signature verification requires the secret key or public key.
What is the difference between header, payload, and signature?
Header contains the algorithm, payload contains claims (data), and signature ensures the token wasn't tampered with.