3 Random Secret Key Generator Tools, Compared Honestly

You need a secure random secret — a JWT signing secret, an API key, an encryption key — and want it generated with genuine cryptographic randomness, not Math.random() or something you typed by hand.

Every generator here uses the Web Crypto API’s crypto.getRandomValues() for true cryptographic randomness; the differences are in how many output formats are offered, how adjustable the key length is, and whether extras like bulk generation or custom prefixes are included.

How to judge a random secret key generator tool

Uses genuine cryptographic randomness. Verify the tool explicitly states it uses crypto.getRandomValues() or equivalent — a generator built on Math.random() is not suitable for security-sensitive keys, since it’s not cryptographically secure.

Offers the format you need. Hex, Base64, and URL-safe Base64 each suit different contexts — a JWT secret, a URL token, and a config file value might each want a different encoding.

Lets you adjust byte length. Different use cases need different key strengths — 128-bit versus 256-bit versus 512-bit — a fixed-length generator limits flexibility.

Never persists the generated key anywhere. A secret key generator that stores generated values (even locally) creates an unnecessary risk — the safest tools explicitly state nothing is saved to cookies, localStorage, or history.

The comparison

Facts checked August 2026; tools change their plans.

RandomKeygen

RandomKeygen offers over 50 specialized generators covering passwords, passphrases, UUIDs, JWT secrets, API keys, encryption keys (AES, RSA), and SSH keys, all generated locally using crypto.getRandomValues() with nothing transmitted to a server, no signup, no premium tier, and no generated-value history.

It isn’t for someone who wants a single focused key generator — the breadth of 50+ specialized generators is a strength for exploring different key types but more than a quick single-secret task needs.

HexHero

HexHero generates cryptographically secure random keys as a browser-based alternative to openssl rand, supporting Base64, hexadecimal, URL-safe Base64, and alphanumeric formats, with four key strength options from 128-bit to 512-bit (256-bit/32 bytes as the default), explicitly stating keys aren’t stored in cookies, localStorage, or any persistent storage.

It isn’t for someone who wants adjacent generator types (passwords, SSH keys) in the same tool — it’s focused specifically on raw secret key generation.

generate-random.org

generate-random.org generates API keys client-side in 6 formats (alphanumeric, hex, base64, base64url, UUID v4, numeric) with customizable length (8-256 characters), optional custom prefixes (sk_, pk_, api_, test_, prod_) for key identification, bulk generation of up to 25 keys at once, and export options as text, CSV, or JSON, compliant with NIST SP 800-90A standards.

It isn’t for someone who just wants one quick key — the prefix and bulk-generation features are genuinely useful for API key management workflows but more setup than a single secret needs.

Random Secret Key Generator

Our tool generates a cryptographically secure random secret key in hex, Base64, or URL-safe Base64, with adjustable byte length — entirely in your browser.

A real limitation: it doesn’t offer bulk generation or custom prefixes — for generating multiple labeled API keys at once, generate-random.org’s bulk and prefix features cover that additional workflow.

Which one to pick

If you want a single secure secret key quickly in your preferred format, use our Random Secret Key Generator.

If you want related generator types (passwords, SSH keys, UUIDs) in the same place, use RandomKeygen.

If you want the widest format choice with explicit no-persistence guarantees, use HexHero.

If you’re managing multiple API keys and want bulk generation with prefixes, use generate-random.org.

How to do it with Random Secret Key Generator

1. Open the Random Secret Key Generator.
2. Choose your format — hex, Base64, or URL-safe Base64.
3. Adjust the byte length and generate your secure random key.

Browse the full tools directory for more free, browser-based security tools.

Frequently asked questions

Is there a free random secret key generator that doesn’t need an account?

Yes. Our Random Secret Key Generator and all three alternatives here work without requiring signup.

Why does it matter whether a key generator uses crypto.getRandomValues() instead of Math.random()?

Math.random() is a pseudo-random number generator designed for speed and general-purpose use, not security — its output can, in principle, be predicted or reproduced given enough samples, which makes it unsuitable for anything security-sensitive. crypto.getRandomValues() (from the Web Crypto API) draws from a cryptographically secure random source specifically designed to be unpredictable, which is the standard required for generating secrets, keys, or tokens that need real security guarantees.

What format should I choose for a specific use case?

Hex is a common choice for encryption keys and low-level cryptographic material since it maps directly to raw bytes; Base64 is more compact and commonly used for API keys and general secrets; URL-safe Base64 (using - and _ instead of + and /) is specifically needed when the key or token will end up in a URL, query parameter, or filename where standard Base64 characters could cause encoding issues, a distinction covered in RFC 4648.

Final thought

Match the byte length to the actual security requirement — 256 bits (32 bytes) is a solid general-purpose default for most secrets, but check whether your specific use case (like a particular JWT library or encryption standard) has a documented minimum length requirement before assuming the default is sufficient.

Try the free Random Secret Key Generator