Uttir

JWT Decoder

Decode a JWT’s header and payload and check its expiration — without sending it anywhere.

Tokens are decoded locally in your browser. Paste-sensitive JWTs here safely — nothing is transmitted.

What is jwt decoder?

A JSON Web Token packs two Base64URL-encoded JSON objects — the header and the payload — plus a signature. This decoder shows both objects as readable JSON and highlights the exp claim, telling you whether the token is expired and by how much.

Unlike web-based debuggers that ask you to paste secrets into their servers, Uttir decodes entirely client-side, making it safe for production tokens.

How to use it

  1. Paste the token

    The full header.payload.signature string.

  2. Inspect the claims

    Header and payload render as formatted JSON.

  3. Check expiry

    If an exp claim exists, a badge shows whether it is expired.

Examples

Typical payload

Common claims: sub (subject), name, iat (issued at).

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c

Result: { "sub": "1234567890", "name": "John Doe", "iat": 1516239022 }

Frequently asked questions

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