Client-Side UtilityLocal memory execution • Zero server telemetry
Cryptographic Password & Key Generator
Generate cryptographically secure random passwords and encryption keys using the browser Web Crypto API with zero modulo bias and zero network transmission.
SMaintained by Security Tools
Published Last verified
Generator Settings
Min: 8, Max: 64
Included Character Sets:
Generated Value
100% in-browser memory
Cryptographic Entropy Analysis
Live computedShannon Entropy
131 bitsVERY STRONG
Character Pool Size
86 charactersPassword Length
16 charactersSecurity Assessment
Very Strong against brute-forceEntropy Quality
CSPRNG (Web Crypto API)Zero modulo bias rejection sampling
SMaintained by Security Tools
Published Last verified
Calculation Methodology & Formula
Generates cryptographically random bytes via crypto.getRandomValues(). Shannon entropy is calculated as length × log2(poolSize) to measure resistance against brute-force attacks.
Entropy (Bits) = L × log2(N)Worked Example: High-Entropy 20-Character Key
20-character password containing uppercase, lowercase, numbers, and symbols.
length:20 characters
character Sets:All 4 pools
Expected Output~131 Bits of Entropy (Very Strong)
With a 94-character pool, 20 characters provide over 130 bits of cryptographic entropy.
Technical Constraints & Limitations
- Passwords generated in-memory are cleared when you navigate away or refresh the page.
Frequently Asked Questions
Is it safe to generate production passwords here?
Yes. This tool uses window.crypto.getRandomValues(), the exact same cryptographically secure pseudorandom number generator (CSPRNG) used by operating systems. Zero bytes leave your browser.
What is Shannon entropy in passwords?
Entropy measures unpredictable randomness in bits. Passwords with over 80 bits of entropy require billions of compute years to brute-force with modern hardware.