Free browser-based tool

JWT Decoder - Decode Tokens Locally

Inspect a JSON Web Token header, payload, and time claims directly in your browser.

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JWT Decoder - Decode Tokens Locally

What is this tool?

A JWT is a compact token format made of Base64URL-encoded sections. Developers often decode tokens to inspect claims such as issuer, subject, audience, roles, issued-at time, and expiration time.

How to use it

Paste a three-part JWT to view its decoded JSON header and payload, then check claims such as exp, iat, iss, and aud.

Common uses

  • Inspect authentication claims while debugging an API.
  • Check issuer, audience, roles, and subject values.
  • Convert iat, nbf, and exp claims into readable dates.

Common mistakes

  • A decoded JWT is not necessarily valid; its signature must still be verified.
  • Do not share active production tokens because they may grant access.
  • JWT timestamps normally use seconds, while some systems use milliseconds elsewhere.

Practical example: Checking JWT expiration

Paste a token and compare its exp date with the current time. An expired token should be refreshed or rejected by the application.

Privacy

This tool is designed to process your input locally in the browser. Avoid entering passwords, private keys, or other sensitive production data into any online tool.

Frequently asked questions

Does this verify the JWT signature?

No. Decoding a token does not verify its signature or prove that it is trustworthy.

Should I paste production tokens?

Avoid sharing sensitive production tokens with any online tool, even when processing is local.

What does exp mean in a JWT?

The exp claim is the expiration time. It is normally a Unix timestamp in seconds.

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