JWT Decoder

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Decoded header and payload appear here when you paste a valid JWT.

A fast, private JWT decoder for developers

Paste any JSON Web Token to instantly view its header and payload as prettified, syntax-highlighted JSON. Common claims like exp, iat, and nbf are converted to readable timestamps so you can spot expired tokens at a glance.

Everything runs locally in your browser. Tokens are never uploaded — ideal for debugging auth flows, inspecting API responses, and learning how JWTs are structured.

  • Decode header & payload
  • Readable exp / iat / nbf times
  • Syntax-highlighted JSON
  • Copy header, payload, or token
  • Sample JWT included
  • 100% client-side & free

Frequently asked questions

What is a JWT decoder?

A JWT decoder reads a JSON Web Token and splits it into its three parts: header, payload, and signature. It Base64URL-decodes the header and payload so you can inspect claims like sub, exp, and iss in plain JSON.

Is it safe to paste my JWT here?

Decoding happens entirely in your browser. The token is never sent to a server. Still treat JWTs as secrets — anyone with the token can often act as you until it expires.

Does this tool verify the signature?

No. This decoder only parses and displays the token structure. Signature verification requires your signing secret or public key and is not performed here.

Why does my token show as invalid?

Common causes: missing dots (JWTs need exactly two), invalid Base64URL encoding, or JSON that is not an object in the header or payload.

What do exp, iat, and nbf mean?

They are Unix timestamps in seconds. exp is expiration, iat is issued-at, and nbf is not-before. This tool converts them to readable dates and shows whether the token is expired.

Can I decode JWE (encrypted) tokens?

This tool is built for signed JWTs (JWS) with three dot-separated segments. Encrypted JWE tokens use a different format and are not supported.

Is the JWT decoder free?

Yes. It is free, requires no signup, and works offline after the page loads.