JWT Signature Verifier
Verify HMAC (HS256, HS384, HS512) or RSA/ECDSA signatures of JWT tokens client-side using Web Crypto API. Confirm payload integrity locally.
1 How to Use JWT Signature Verifier
- 1. Paste JWT token.
- 2. Enter shared secret key or public key.
- 3. See instantaneous Valid / Invalid verification badge.
⚙️ Cryptographic Specifications
- Algorithm
- HMAC / RSA
- Execution Engine
- Web Cryptography API (SubtleCrypto)
- Environment
- Client Browser Sandbox
- Network Telemetry
- 0 Bytes (Zero Server Transmission)
🛡️ Security & Compliance
Enterprise developers can safely execute this tool with production secrets. Because execution takes place entirely within your browser's local V8 JavaScript runtime, no payloads are transmitted over HTTP, cached on third-party proxies, or stored in server logs.
Verified Safe for SOC2, HIPAA, and GDPR developer compliance audits.
Frequently Asked Questions
Can this verify RS256?
Yes, provide the PEM public key or JWK to verify asymmetric signatures.
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