Security
Free JWT Decoder Online
Decode JWT headers and payloads instantly. Inspect claims, expiration dates, and algorithms. Does not verify signatures — for debugging only.
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Frequently Asked Questions
- What is a JWT decoder?
- A JWT decoder extracts and displays the header and payload from a JSON Web Token (JWT) without verifying the cryptographic signature.
- Does this verify JWT signatures?
- No. This tool only decodes Base64URL-encoded header and payload sections. Signature verification requires the secret key and is not performed.
- Is it safe to paste my JWT here?
- Decoding happens entirely in your browser — nothing is uploaded. However, avoid pasting production tokens with sensitive claims.
- What are the three parts of a JWT?
- A JWT has three dot-separated parts: Header (algorithm and type), Payload (claims and data), and Signature (verification hash).
- Can I see token expiration?
- Yes. If the payload contains an exp (expiration) claim, the decoder shows the expiry date and whether the token has expired.