Securing the Modern Auth Layer
JSON Web Tokens are the heartbeat of modern authentication. NexsaConvert provides a secure, client-side workstation to dissect your tokens, ensuring that claims are valid, expiration dates are correct, and security headers meet industry standards like RFC 7519.
Three-Part Anatomy: Base64URL
A JWT consists of three parts—Header, Payload, and Signature—separated by dots. Our engine automatically handles the Base64URL decoding, providing a syntax-highlighted JSON view of your claims, permissions, and session data without ever sending your sensitive tokens to a server.
Debugger Specs
JWT Security FAQs
Is it safe to paste my JWT here?
Yes. NexsaConvert processes everything in your browser. Unlike other online debuggers, your token is never uploaded or logged on our servers.
What are 'Reserved Claims'?
These are predefined fields like `iss` (issuer), `exp` (expiration), and `sub` (subject). They are NOT mandatory but are highly recommended for standard-compliant auth.
Can a JWT be tampered with?
If someone changes the payload, the signature will no longer match. However, unless the token is encrypted (JWE), the data inside is visible to anyone who has the token.
Difference between HS256 and RS256?
HS256 uses a single secret key for both signing and verification. RS256 uses a private key for signing and a public key for verification, making it more secure for public APIs.