The Code Codex
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JWT Decoder

Inspect a JWT's header, payload and dates (iat, exp, nbf) without sending it to any server.

The link keeps what is on screen.
How is it calculated?
The signature is not verified — that requires the issuer's key.
See the code ↗

Processed in your browser; nothing is sent.

⌨️ Use from the terminal (JSON)

This tool also runs outside the site: the cli.js script uses the same logic as this page and returns the result as JSON. Parameters are the same as this page's URL — copy the command below with the values on screen.

Deno
deno run -q "https://thecodecodex.com/cli.js?tool=jwt"
Node.js / Bun
curl -s https://thecodecodex.com/cli.js | node --input-type=module - jwt token=…
ParameterDescriptionDefault
tokentoken JWT—

Requires Deno, Node.js or Bun. With Deno the script runs with no permissions: it cannot read files or access the network. Central Bank indicators are from the day the site was published.

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