Online JWT Signer & Verifier — Securely Generate & Verify JWTs

Sign JWT

Header (JSON):

Payload (JSON):

Secret Key:

Algorithm:

Generated JWT:

Verify JWT

JWT Token:

Secret Key:

Verification Result:

Decoded Header:

Decoded Payload:

Frequently Asked Questions (FAQ)

Is this JWT tool secure? Where is my secret key stored?

Yes, this tool is secure. All signing and verification operations happen entirely within your web browser using JavaScript. Your secret key is never sent to any server and is only used locally for the cryptographic calculations.

What algorithms are supported for signing and verification?

This tool currently supports HMAC signing algorithms using SHA-256, SHA-384, and SHA-512 (HS256, HS384, HS512). Ensure the algorithm selected matches the one expected by the verifying party.