JWT Decoder

Decode any JSON Web Token (JWT) to inspect its Header, Payload, and Signature. Supports HS256, RS256, ES256 and other algorithms. Decoding happens entirely in your browser — your token is never sent anywhere.

Header

—

Payload

—

Signature

—

Common Use Cases

Use the JWT Decoder online for these scenarios:

API debugging: Quickly view JWT Header, Payload, Signature outside Postman/cURL
Security audit: Check if JWT contains sensitive data (passwords etc. should never be in JWT)
Learning OAuth: Understand Token structure of OAuth 2.0 / OpenID Connect
Token expiration check: View `exp` field to verify token validity
Troubleshooting: Confirm token format and signature when getting 401 errors

Frequently Asked Questions

Here are the most common questions:

Q: Is JWT encrypted?
A: No. JWT is signed by default (HS256/RS256), not encrypted. Anyone can read the Payload. Sign-only-not-encrypt is a design choice.

Q: Is JWT secure?
A: Depends on implementation. Must use HTTPS, never put sensitive data, keep signing keys secret, set reasonable expiration.

Q: JWT vs Session — which is better?
A: Each has pros/cons. JWT is stateless, good for distributed systems. Session is server-controlled, good for traditional apps.