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Developer Utility

JWT Sign / Verify (HMAC) Tool

Sign and verify JWTs with HMAC algorithms for local testing workflows.

Language: JWTUtility: GenerateUtility: ValidateUtility: Inspect
Use Sign JWT or Verify JWT.

What This Tool Does

Sign and verify JWTs with HMAC in-browser for local development and auth testing.

Use it to inspect or transform input quickly, then carry validated output into code, tests, or API requests.

Common Use Cases

  • Generate HS256 test tokens with controlled claims.
  • Verify incoming HMAC JWTs during debugging.
  • Prototype token flows without external signing services.

Common Pitfalls

  • HMAC test signing is not a replacement for production key management.
  • Token validity still depends on claim semantics like exp/nbf.

FAQ

  • Does this support HS256/HS384/HS512?

    Yes, common HMAC JWT algorithms are supported.

  • Can I use this for RS256 certificates?

    This tool focuses on HMAC workflows in MVP scope.

  • Does this tool send data to a backend?

    Most tools process input client-side in your browser unless explicitly noted.

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