Generate highly secure random passwords or memorable passphrases locally. Calculate Shannon entropy metrics in real-time and control character configurations natively. Your data never leaves your device.
Creating highly secure passwords takes just three simple steps:
Select character limits (12+ characters recommended).
Toggle numbers, upper/lowercase, symbols, and bulk counts.
Click copy to save your secure password locally.
Generates entropy natively using system-level cryptographic arrays.
Calculations occur strictly locally — never uploaded or saved.
No subscription, no watermark banners, no limits.
Adjust lengths, character ranges, and count boundaries.
View mathematical bits of entropy and cracking times instantly.
Engineered for high performance on both mobile and desktop viewports.
In cryptography, the security of a password is measured using **Information Entropy (Shannon Entropy)**, represented in bits. This value indicates the size of the search space that a malicious system would have to search during a brute-force attack. The formula to calculate bits of entropy is:
Where:
Adding different character classes increases the base of our logarithmic formula, expanding the total search space exponentially:
| Entropy Score (Bits) | Brute-Force Complexity | Time to Crack (100 Billion guesses/sec) | Security Classification |
|---|---|---|---|
| Less than 40 bits | $2^{40}$ Operations | Less than 12 seconds | Very Weak |
| 40 to 59 bits | $2^{50}$ Operations | Hours to Days | Weak |
| 60 to 79 bits | $2^{70}$ Operations | Months to Years | Moderate |
| 80+ bits | $2^{80}$ Operations | Centuries | Secure |
Standard programming random functions (such as `Math.random()` in older JavaScript engines) utilize algorithms like LCG or Xorshift. While these are fast, they are mathematically predictable. If an attacker knows a few output values, they can reconstruct the internal state and predict all future passwords.
To prevent this, our generator uses the browser's native **Web Crypto API** (`crypto.getRandomValues`). This API accesses the system's cryptographically secure pseudo-random number generator (CSPRNG), which gathers actual hardware entropy from device drivers and system events. This ensures that every generated password is mathematically unpredictable and secure.
Yes. The entire generation process is handled locally on your device using browser cryptographic APIs (`crypto.getRandomValues`), meaning your passwords are never sent to external servers or recorded.
Shannon Entropy measures the randomness and strength of a password in bits. Passwords with more than 80 bits of entropy are highly secure and practically impossible to brute-force with modern hardware.
Passphrases combine multiple random words (e.g., `correct-horse-battery-staple`). They are easy for humans to remember but provide extremely high entropy, making them highly secure against automated dictionary attacks.
It filters out easily confused characters (like `i, l, 1, L, o, 0, O`), making it easier to read and manually type the password on other devices.
No. We do not store, log, or track any generated data. We recommend using a trusted password manager (like Bitwarden) to save your credentials securely.