JWT Decoder
Decode any JWT token to inspect its header, payload, and claims. Validates structure, checks expiry, and explains iat, exp, sub, and iss — all in your browser, completely private. Pro: batch decode multiple tokens and export as JSON.
Frequently Asked Questions
How do I decode a JWT token?▼
Paste the full JWT string (three Base64-encoded parts separated by dots) into the input field. The tool instantly splits it into header, payload, and signature sections and displays all claims in a readable format.
Is it safe to decode JWT tokens online?▼
Yes, with this tool. Everything runs in your browser — the JWT is never sent to any server. However, avoid pasting production tokens into tools that send data to a backend, as JWTs may contain sensitive claims.
What are the common JWT claims (iat, exp, sub)?▼
iat (Issued At) is when the token was created. exp (Expiration Time) is when it expires. sub (Subject) identifies the user. iss (Issuer) identifies who created the token. aud (Audience) specifies who the token is intended for.
Can I verify a JWT signature with this tool?▼
This tool decodes and inspects JWT tokens but does not verify signatures, as that requires the secret key or public key. For signature verification, use your backend or a library like jsonwebtoken (Node.js) or PyJWT (Python).
What is the difference between JWT, JWS, and JWE?▼
JWT (JSON Web Token) is the general concept. JWS (JSON Web Signature) is a signed JWT — the most common type, with a verifiable signature. JWE (JSON Web Encryption) is an encrypted JWT where the payload is hidden. Most 'JWT tokens' you encounter are JWS.
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