How Web Crypto Accesses Hardware Entropy
When you click "Generate Key", the browser calls `window.crypto.getRandomValues(new Uint8Array(byteLength))`. Modern operating systems (Linux `/dev/urandom`, macOS `getentropy()`, Windows `BCryptGenRandom`) harvest entropy from hardware interrupts, thermal noise, and CPU jitter to seed the cryptographic generator.
Why Zero-Storage Matters
A fundamental vulnerability in poorly written developer tools is caching generated credentials in `localStorage` or session cookies. Our tool operates under an immutable zero-storage principle:
1. The byte array exists solely in ephemeral JavaScript memory.
2. When you refresh, navigate away, or click Clear, the secret is immediately garbage collected.
3. No analytics payload ever touches the generated value.
Generate in Browser
Launch GeneratorNeed a cryptographically secure JWT secret right now?
Generate 128 to 512-bit keys in Hex or Base64 using Web Crypto with zero server transmission.
Frequently Asked Questions
Does the server ever see my generated secret?
No. All operations run 100% client-side in your local browser sandbox. You can inspect the network tab in Developer Tools to verify zero outgoing HTTP requests.
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