Build custom JSON Web Tokens and sign with HMAC (HS256, HS384, HS512) via Web Crypto API.
Execution runs 100% locally inside the browser sandbox using HTML5 Canvas, Web Cryptography Subtle API, and Web Workers. Zero egress.
Zero network latency. Operates completely offline with zero dependencies on third-party backend servers or cloud services.
Built according to official RFC specifications, cryptographic test vectors, and enterprise-grade data transformation standards.
Customize your JOSE header algorithm and JSON claims payload.
Type your HMAC secret phrase.
Copy the Base64URL-encoded and cryptographic signature verified JWT token.
Never. All cryptographic HMAC signing operations run 100% in your browser using window.crypto.subtle.
HS256 (SHA-256), HS384 (SHA-384), and HS512 (SHA-512) are fully supported.
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