Swrice Tools JWT Decoder
Paste a JSON Web Token below to instantly decode its header and payload, and see whether it has expired. Everything happens locally in your browser — your token is never sent anywhere. This decodes a token; it does not verify its signature.
How to use the JWT Decoder
- Paste a JWT into the box above.
- It decodes automatically as you type, or click Decode.
- The header and payload appear as formatted JSON, with an expiry summary if the token has an "exp" claim.
- Use Copy Payload to grab the decoded payload.
Frequently asked questions
Is this JWT Decoder free to use?
Yes, it is completely free with no sign-up or usage limits.
Is my token uploaded anywhere?
No. Decoding happens entirely in your browser using JavaScript — your token is never sent to a server, which matters since JWTs often carry sensitive session data.
Does this verify the signature?
No, this is a decoder, not a verifier. It reads and displays the header and payload, which are just Base64-encoded JSON and not encrypted — anyone can decode them. Verifying the signature requires the secret or public key used to sign the token, which this tool never asks for.
Why do I see "expired" next to the expiry date?
If the token's payload has an "exp" claim (a Unix timestamp), this tool compares it to the current time and flags whether the token has already expired.
What is a JWT?
A JSON Web Token is a compact, URL-safe token made of three Base64url-encoded parts separated by dots: a header (algorithm/type), a payload (claims/data), and a signature (to verify it hasn't been tampered with) — commonly used for authentication and information exchange.