JWT Decoder
What is JWT Decoder? (Quick Answer)
JSON Web Token decoder Free online tool, no registration required, 100% client-side processing.
JSON Web Token decoder
By Craftisle Team
About JWT Decoder — Free Online Tool
How to Use JWT Decoder — Step by Step
- Paste a JWT
Copy and paste the JWT string (starts with eyJ...) into the decoder.
- View decoded parts
The header (alg, typ) and payload (sub, exp, iat) are displayed in readable JSON.
- Check expiration
The tool highlights if the token is expired based on the exp claim.
Use Cases for JWT Decoder
API debugging
Inspect JWT payloads returned from authentication endpoints.
Security auditing
Verify that JWTs don't contain sensitive data in the payload (they are signed, not encrypted).
Learning JWT structure
Understand the three parts of a JWT: header, payload, signature.
FAQ — JWT Decoder Free Online Tool
Can I verify the signature?
This tool decodes (base64url) but doesn't verify signatures. For signature verification, use your backend's JWT library with the secret key.
Is a JWT encrypted?
No. JWT payloads are only base64url-encoded, not encrypted. Anyone can decode them. Never put secrets in a JWT payload.
What does exp mean?
exp is the expiration time (Unix timestamp). After this time, the token should be rejected by the server.