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JWT Secret Generator – Free & Secure
Free JWT secret generator. Create cryptographically secure HMAC signing keys in Base64, Hex, or ASCII for HS256, HS384, and HS512 — runs locally in your browser.
JWT Secret Generator
Generate cryptographically secure HMAC signing keys for HS256, HS384, and HS512 — runs entirely in your browser
Free JWT secret generator using the Web Crypto API. Choose 128–512-bit key lengths and Base64, Hex, or ASCII output for HS256, HS384, or HS512 HMAC algorithms. All secrets are generated locally — nothing is ever sent to a server.
Recommended — HS256 minimum
Generate multiple secrets for JWT key rotation workflows
All JWT secrets are generated locally using the Web Crypto API. They never leave your device or touch any server.
JWT Secret Security Best Practices
- Store JWT secrets in environment variables or secret managers like AWS Secrets Manager, Doppler, or Vault
- Never commit secrets to version control — add .env to .gitignore
- Rotate JWT signing secrets regularly (every 90 days) using batch generation
- Use at least 256-bit keys for HS256 in production environments
- Never expose JWT signing secrets in client-side JavaScript or browser code
What is JWT Secret Generator?
Generate production-ready JWT signing secrets using the Web Crypto API — fully client-side, no data ever sent to a server. Choose from 128-bit to 512-bit key lengths and output in Base64 (URL-safe), Hexadecimal, or ASCII. Designed for HS256, HS384, and HS512 HMAC algorithms. Supports batch generation for key rotation workflows and one-click copy for fast integration into .env files or secret managers like AWS Secrets Manager, Doppler, or Vault.
JWT Secret Generator Features
HS256 / HS384 / HS512 Ready
Select 256, 384, or 512-bit keys to exactly match your JWT algorithm's minimum requirement — no guesswork.
Base64, Hex & ASCII Output
Pick Base64 (URL-safe) for modern frameworks, Hex for legacy systems, or ASCII for custom implementations.
100% Client-Side — Never Leaves Your Browser
All secrets are generated using the Web Crypto API locally. Nothing is transmitted to any server.
Batch Generation for Key Rotation
Generate up to 10 secrets at once to support key rotation strategies without repeating manual steps.
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JWT Secret Generator FAQ
A JWT secret is a cryptographic key used to sign JSON Web Tokens (JWTs) with HMAC algorithms like HS256, HS384, or HS512. It verifies that the token wasn't tampered with. The server signs the token on issue, then re-verifies the signature on each request.
Use at least 256-bit for HS256, 384-bit for HS384, and 512-bit for HS512. RFC 7518 requires the HMAC key to be at least as long as the hash output. Shorter keys will cause validation failures in strict JWT libraries.
Base64 (URL-safe) is recommended for most frameworks including Node.js, Next.js, and Python. Use Hex if your system or library requires hex strings. ASCII is useful for systems with character-encoding constraints.
Yes — this tool runs entirely in your browser using the Web Crypto API. No secrets are sent to any server or logged anywhere. You can verify this by running it offline after the page loads.
Copy the secret and paste it into your .env file as JWT_SECRET=your_secret_here. In Node.js, access it via process.env.JWT_SECRET and pass it to your JWT library (e.g., jsonwebtoken: jwt.sign(payload, process.env.JWT_SECRET, { algorithm: 'HS256' })).
Key rotation is the practice of periodically replacing your JWT secret with a new one to limit exposure if a key is compromised. Use the batch generation feature to generate replacement keys and update them in your secret manager (AWS Secrets Manager, Doppler, Vault, etc.) without downtime.