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JWT Decoder

Paste a JWT token to decode its header and payload. Your token never leaves the browser.

Header

Payload

Frequently Asked Questions

What is a JWT token?

A JWT (JSON Web Token) is a compact, URL-safe way to transmit claims between parties. It consists of three parts: a header (algorithm info), a payload (claims/data), and a signature (for verification). JWTs are widely used for authentication, authorization, and information exchange in web applications.

Is it safe to decode JWTs in a browser tool?

Yes, for decoding purposes. The JWT header and payload are base64-encoded, not encrypted — anyone with the token can decode them. The signature is what protects the token from tampering. ToolsStack decodes entirely client-side, so your JWT never leaves your browser. However, never share JWTs that contain sensitive data.

Does this tool verify JWT signatures?

No. This tool decodes and displays the header and payload claims for inspection. It does not verify signatures because JWT verification requires a secret key or public key that should never be entered into a web tool. Signature verification should be done on your own server.