Tool capabilities
- Input
- TXT
- Output
- JSON · TXT
How to use JWT Signature Verifier
Verify an HS256 JWT signature with your shared secret and inspect expiration and not-before claims. This jwt signature verifier works directly in your browser and is free to use without an account.
- Paste the message or JWT into the input.
- For HS256 verification or HMAC, enter the UTF-8 shared secret and run the calculation.
- Inspect and copy the result. Clear the inputs when finished.
JWT Signature Verifier · Example
Input
HS256 JWT + your shared secret
Output
Signature match, expiration and not-before results
Results depend on the supplied token and key. Issuer and audience require separate checks.
Usage notes
Inputs and results are processed on this device. Tool content is not sent to a processing server.
JWT decoding does not establish trust. HS256 verification checks a signature and reports time claims; it does not validate issuer, audience or application authorization.
Tokens and secret keys are held in memory and are never autosaved.