JWT Decoder Online

JWT inspection checklist

Use this decoder when debugging OAuth, OpenID Connect, API bearer tokens, staging logins, webhooks, or authorization headers. Start by checking the token algorithm, key ID, issuer, audience, subject, expiry time, and any scope or role claims that control access. A readable payload is not proof that the token is valid; it is only a faster way to understand what the token says.

• Confirm iss matches the identity provider you expect.
• Compare aud with the API or client that should accept the token.
• Check exp and nbf before chasing backend bugs.
• Look for missing scopes, roles, tenant IDs, or permissions.

Safe JWT debugging tips

JWTs can contain session identifiers, emails, account IDs, or authorization grants. For production issues, prefer redacted sample tokens, short-lived test users, or server-side verification logs. Never treat a decoded JWT as trusted until the signature, issuer, audience, and expiry have been verified by code that owns the correct keys.

How to use this free tool

1. Enter or upload your content.
2. Click the main action button.
3. Review and copy the result instantly.

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FAQ

Does this verify the JWT signature?

No. This JWT decoder is for reading header and payload JSON only. Use your backend, identity provider, or trusted signing keys to verify signatures before trusting any token.

Is my token uploaded?

No. Decoding happens locally in your browser after the page loads. Avoid pasting production secrets into any shared machine or screen recording.

What JWT claims should I check?

Common claims include exp for expiry, iat for issued time, iss for issuer, aud for audience, sub for subject, plus application-specific scopes, roles, tenant IDs, and permissions.

Can it decode base64url claims?

Yes. Standard JWT base64url header and payload sections are decoded and formatted as JSON for easier review.