Does this JWT decoder send my token to a server?

No. Decoding happens entirely in your browser. This tool is client-side only.

Can this tool verify JWT signatures?

No. This tool is for decoding and inspection only. Signature verification requires the correct secret or public key.

It indicates an unsigned token. You should treat it as untrusted in production authentication flows.

Paste a JSON Web Token to decode the header and payload instantly. Everything runs locally in your browser.

JWT (header.payload.signature)

Waiting for input…

No temporal claims detected yet.

{}

{}

Is this JWT decoder private?

Yes. Decoding happens entirely in your browser. The token is not uploaded by this tool.

Does decoding mean verification?

No. Decoding only reads token contents. Verification requires cryptographic validation with the proper key.

Why does alg=none show a warning?

Because alg: none indicates an unsigned token. It should not be trusted for authentication in production systems.

Can I generate a demo JWT?

Yes. Use Generate Sample Token to create an unsigned example for testing and learning.