Developer Tools

JWT Signature & HMAC-SHA256 Secret Verifier

Verify JSON Web Token signatures with your HMAC-SHA256 secret key locally in your browser using the Web Crypto API.

Paste JWT Token (Encoded)

HMAC-SHA256 Secret Key

Decoded Payload

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NO. Verification uses the native browser Web Crypto API (SubtleCrypto)—zero data leaves your device.

Supports standard HS256 (HMAC with SHA-256) signature verification.

Yes, the payload JSON is automatically decoded and formatted alongside the verification check.