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Configure your key settings above
Click Generate to produce cryptographically secure secrets🔒 Generated entirely in your browser — nothing is sent to any server
// generate secure random secrets instantly
Generate cryptographically secure random secrets for JWT signing, session tokens, encryption keys, and API authentication. Free, browser-based, no upload required.
Configure your key settings above
Click Generate to produce cryptographically secure secretsChoose from JWT, session, encryption, API key, or custom length presets.
Select hex, Base64, URL-safe Base64, or alphanumeric depending on your stack.
Click Generate, then copy individual keys or all at once. View usage snippets for your language.
This tool uses the Web Crypto API (crypto.getRandomValues) to generate cryptographically secure random bytes directly in your browser. No data leaves your machine — ever. The output meets NIST randomness standards suitable for production security secrets.
Yes. The generator uses crypto.getRandomValues() — the same Web Crypto API used by browsers for TLS. All generation happens locally in your browser; nothing is transmitted to any server. The output is cryptographically indistinguishable from random, meeting NIST SP 800-90A standards.
Both encode the same random bytes, just differently. Hex uses characters 0–9 and a–f (2 chars per byte, longer strings). Base64 uses A–Z, a–z, 0–9, +, / (shorter but may need escaping in URLs). Base64 URL-safe replaces + with - and / with _ — ideal for JWTs and query parameters. Choose based on your framework's expectations.
NIST recommends a minimum of 256 bits (32 bytes) for HMAC-based JWT secrets (HS256). For HS384, use at least 384 bits; for HS512, use 512 bits. Using a shorter key than the algorithm's output length weakens security. This tool defaults to 512-bit for maximum safety.
Yes — that is one of the primary use cases. Select "Base64" or "Hex" format, generate your key, and paste it as the value of your environment variable (e.g. JWT_SECRET=<key>). The ".env" snippet tab shows you the exact format. Wrap in quotes if your key contains special characters.
A JWT secret is used for HMAC signing to verify authenticity (the data is still readable). An encryption key (e.g. AES-256) encrypts data so it cannot be read without the key. Use JWT secrets for stateless authentication tokens. Use encryption keys when you need to protect the confidentiality of stored or transmitted data.
Never. Secret keys must be kept out of git repositories and source code. Store them in environment variables, a secrets manager (AWS Secrets Manager, HashiCorp Vault, Doppler), or a .env file that is listed in .gitignore. Rotate any key that was accidentally committed immediately.
Rotation frequency depends on risk. At minimum: rotate immediately if compromised, rotate on team member offboarding, and rotate annually as hygiene. High-security applications rotate session secrets every 90 days. JWT secrets should have short-lived tokens (15–60 min expiry) so key rotation impact is minimal.
Both are equally secure. This tool is more convenient if you don't have terminal access, need to generate multiple keys quickly, want code snippets immediately, or are on a shared machine where terminal history could be a concern. For CI/CD pipelines, openssl rand -base64 64 is equally valid.
A secret key generator is a tool that produces cryptographically secure random byte sequences suitable for use as cryptographic secrets in web applications and security systems. Unlike regular random strings, cryptographic secrets require high-entropy randomness that is computationally infeasible to predict or reproduce — a property that standard Math.random() calls cannot provide.
This tool uses the browser's built-in Web Crypto API (crypto.getRandomValues()) to generate true cryptographic randomness, the same source used by your browser to establish HTTPS connections. Every key generated meets or exceeds NIST SP 800-90A randomness recommendations.
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JSON Web Tokens (JWTs) rely on a shared secret (for HMAC algorithms) or a key pair (for RSA/ECDSA) to sign and verify tokens. When using HS256, HS384, or HS512, the secret must be at least as long as the hash output: 256 bits for HS256, 384 for HS384, and 512 for HS512. Using a shorter secret than the algorithm expects is a common misconfiguration that weakens security significantly.
A strong JWT secret should be:
Web frameworks like Express.js, Django, Laravel, and Rails use session secrets to sign cookies and session identifiers. This prevents tampering: a valid session cookie's signature can only be produced by someone who knows the secret. If an attacker discovers your session secret, they can forge session cookies for any user — effectively bypassing your entire authentication system.
Session secrets should be 128–256 bits minimum. This tool's "Session Token" preset generates 128-bit secrets in your chosen format, suitable for most frameworks. For higher-risk applications, use the 256-bit or 512-bit JWT presets instead.
Symmetric encryption algorithms like AES require keys of precise lengths: 128, 192, or 256 bits. AES-256, the most widely deployed, requires exactly 32 bytes of key material. The key must be randomly generated — derived from a password (without proper key derivation like PBKDF2 or Argon2) is insufficient for strong encryption.
The "Encryption Key" preset generates 256 bits of random material, the correct size for AES-256-GCM, AES-256-CBC, and ChaCha20-Poly1305. You can use hex output for languages that accept hex-encoded keys, or Base64 for languages that expect Base64-encoded key material.
API keys serve a different purpose than cryptographic secrets — they identify a caller rather than providing cryptographic guarantees. However, they still need to be unguessable. A 192-bit (24-byte) random API key has approximately 2^192 possible values, making brute-force attacks computationally infeasible for the lifetime of the universe.
Best practices for API keys generated with this tool:
sk_live_) to identify them in logsHexadecimal encodes each byte as two characters (0–9, a–f). A 32-byte key becomes a 64-character hex string. Hex is easy to debug and widely supported in all languages. Use it when your library accepts hex-encoded keys.
Base64 is more compact — 32 bytes becomes a 44-character string. It uses A–Z, a–z, 0–9, +, and /. Standard Base64 can contain characters that require URL encoding, making it unsuitable for direct use in query parameters or HTTP headers without encoding.
Base64 URL-safe replaces + with - and / with _, eliminating URL encoding concerns. This is the format used inside JWT tokens and is ideal for values passed in URLs or HTTP headers. Most modern JWT libraries expect the secret in this format or standard Base64.
Alphanumeric output (A–Z, a–z, 0–9 only) is the safest for environments where special characters might cause issues — shell scripts, config files without quoting, or legacy systems. Note that alphanumeric encoding is slightly less space-efficient than Base64.
Generating a strong secret is only the first step. How you manage that secret determines your actual security posture:
.gitignore for .env files. Scan repositories with tools like git-secrets or truffleHog.If you prefer the command line, these commands produce equivalent secure random output:
openssl rand -hex 64openssl rand -base64 64require('crypto').randomBytes(64).toString('hex')import secrets; secrets.token_hex(64)This browser-based tool is ideal when you need quick generation without terminal access, want to produce multiple keys simultaneously, or need code snippets showing how to use the key in your specific language and framework.