JWT Signature Verifier
Verify a JWT signature against an explicit public JWK and selected claims.
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How to use JWT Signature Verifier
Verify a JWT signature against an explicit public JWK and selected claims. Choose ES256 or RS256 independently of the token header. Signature validity and configured issuer/audience/time checks are reported separately, with no remote key discovery.
- Provide the input and select the documented mode or options.
- Run the tool and review its result and any limits reported below.
- Copy the text result or download a separate output file.
Good to know
- The supplied key must be trusted independently. This is not application authorization, revocation checking or a replacement for server-side validation.
- 20,000 characters per token/key; critical JWS extensions, symmetric/private keys and algorithms other than ES256/RS256 are rejected.
- Processing happens in this browser tab. Inputs and results are not automatically saved or uploaded.
Common questions
What does JWT Signature Verifier process?
Choose ES256 or RS256 independently of the token header. Signature validity and configured issuer/audience/time checks are reported separately, with no remote key discovery.
What happens to my original input?
The tool creates a separate result. Selected files and pasted data remain on this device; inspect the result before using it in another system.
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