JWT Decoder
Decode a JSON Web Token's header and payload. Decoding only — the signature is not verified and the token never leaves your browser.
Header
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Payload
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Claims
JWT Decoder Examples
Click any card to tryHow to Use JWT Decoder
To decode a JWT (JSON Web Token), paste the full token string into the input field. The tool immediately splits the token into its three parts — header, payload, and signature — and displays the decoded header and payload as formatted JSON. The token's expiry time is highlighted and colour-coded to show whether it is currently valid or expired.
This tool decodes and inspects JWT tokens for debugging purposes. It does not verify the signature — to verify a JWT, you would need the signing secret or public key. Use this to inspect token claims such as user ID, roles, expiry time (exp), issued-at time (iat), and any custom claims.
Frequently Asked Questions
What is a JWT? expand_more
A JWT (JSON Web Token) is a compact, URL-safe token format used for securely transmitting information between parties as a JSON object. It consists of three Base64-encoded parts separated by dots: header.payload.signature.
What are the three parts of a JWT? expand_more
The header contains the token type and signing algorithm. The payload contains the claims (data). The signature verifies the token was not tampered with. Only the header and payload are decoded by this tool.
Does this tool verify the JWT signature? expand_more
No. This tool only decodes the Base64-encoded header and payload for inspection. It does not verify the signature. Signature verification requires the signing secret or public key.
Is it safe to paste my JWT into this tool? expand_more
The token is decoded entirely in your browser — nothing is sent to any server. However, be cautious when sharing JWTs containing sensitive user data or authentication tokens, as they grant access to systems if unexpired.
What does the exp claim mean in a JWT? expand_more
The exp (expiration time) claim is a Unix timestamp indicating when the token expires. This tool converts the exp value to a human-readable date and shows whether the token is currently valid or has expired.
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