JWT Claim Explainer

Decode a JWT and explain registered claims locally in your browser.

JWT claim explainer workspace

Explain registered JWT claims locally. Signature trust is not verified.

JWT input

Signature not verified

This decoder reads JWT header and payload locally. It does not verify signatures or trust claims.

Output

Active2027-01-01T00:00:00.000Z

JWT decoded live

Header and payload are decoded locally. Signature trust is not verified.

Claim explainer

issIssuer: https://issuer.example; Issuer that created the token.
subSubject: user_123; Subject the token is about.
audAudience: api; Audience expected to receive the token.
expExpiresActive: 2027-01-01T00:00:00.000Z; Expiration time after which the token should not be accepted.
nbfNot beforeValid now: 2026-01-01T00:00:00.000Z; Not-before time before which the token should not be accepted.
iatIssued at: 2025-12-31T00:00:00.000Z; Issued-at time when the token was created.
jtiJWT ID: token-1; Unique token identifier.

Header

{
  "alg": "none",
  "typ": "JWT"
}

Payload

{
  "iss": "https://issuer.example",
  "sub": "user_123",
  "aud": [
    "api"
  ],
  "exp": 1798761600,
  "nbf": 1767225600,
  "iat": 1767139200,
  "jti": "token-1"
}

Signature

No signature part

Files are processed in your browser. No data is uploaded.

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Questions

Does JWT Claim Explainer verify signatures?

No. It explains decoded claims locally, but it does not verify signatures or trust the token.

Which JWT claims are explained?

It explains common registered claims including iss, sub, aud, exp, nbf, iat, and jti.

Does Utilumo upload my input?

No. This tool is designed for local browser processing and does not send your input to a server.

Do I need an account?

No. Utilumo tools are built to work without accounts or sign-in.