free security tools
← Back to tools

JWT Playground

Interactive JSON Web Token debugger. Paste a token to inspect header, payload, and signature. Edit claims visually, change algorithms, and forge new tokens with a custom secret.

Header

Payload

Claims

Paste a token to see parsed claims

🔏 Forge Token

Click "Sign & Forge" to generate a new token

What is JWT Playground?

Decode, edit, and forge JWT tokens interactively. Test JWT security by modifying claims and observing signature changes.

FAQ

Can I forge valid JWTs?
Only if you know the signing secret. The playground lets you modify claims to see how the signature changes — useful for testing server validation.
What's the difference between Decoder and Playground?
Decoder is read-only. Playground lets you edit the header and payload to test how servers handle modified tokens.

Related Tools