JWT Generator

A JWT generator that creates valid authentication tokens for testing and development. Define the header (algorithm and type), specify payload claims (sub, iss, exp, custom fields), provide a secret key, and the tool generates a signed JWT string ready for API requests. Supports three signing algorithms: HS256 (HMAC with SHA-256), RS256 (RSA signature), and ES256 (ECDSA). The tool uses the Web Crypto API for cryptographic operations — key generation and signing happen entirely in your browser. The payload editor includes helpers for standard claims: click to insert current timestamp, calculate expiration from a duration dropdown, and add custom claims as key-value pairs. Useful for testing API authentication, generating tokens for integration tests, or verifying JWT structure before implementing auth in your backend.