Generate cryptographically random, strong passwords with customizable length and character sets. Free online password generator with strength meter. 100% browser-based - passwords are never transmitted over the internet.
Weak and reused passwords remain the leading cause of account breaches. According to major security reports, over 80% of data breaches involve compromised credentials - either stolen from data breaches, cracked through brute force, or obtained via phishing. A strong, unique password for each account is your first and most important line of defense.
Modern computers can test billions of password combinations per second using GPUs. An 8-character password using only lowercase letters can be cracked in seconds. A 16-character password combining uppercase, lowercase, numbers, and symbols using our generator would take longer than the age of the universe to crack by brute force - even with the most powerful computers available today.
Our password generator uses the browser's Math.random() function to create unpredictable passwords entirely in your browser. No generated password is ever sent to a server, stored, or logged. You can verify this by checking your browser's Network tab in Developer Tools while generating passwords - zero requests will appear.
Important: Never memorize generated passwords - use a password manager (Bitwarden, 1Password, Dashlane, or your browser's built-in manager) to store them securely.
Password strength is determined by entropy - a measure of unpredictability. Higher entropy means more combinations an attacker must try. Here is how character sets affect entropy per character:
| Character Set | Pool Size | Bits/char | 16-char combinations |
|---|---|---|---|
| Lowercase only (a-z) | 26 | 4.7 | 4.4 × 10²² |
| Lowercase + numbers | 36 | 5.2 | 7.9 × 10²⁴ |
| Upper + lowercase | 52 | 5.7 | 5.2 × 10²⁷ |
| Upper + lower + numbers | 62 | 5.95 | 4.7 × 10²⁸ |
| All character types | ~94 | 6.55 | 5.7 × 10³¹ |
8 chars, limited types. Crackable in seconds to minutes.
10-11 chars, some variety. Cracks in hours to days.
12-15 chars, mixed types. Cracks in months to years.
16+ chars, all types. Centuries to crack by brute force.
A password manager generates, stores, and autofills strong unique passwords for every account. You only need to remember one strong master password. Recommended: Bitwarden (open-source, free), 1Password, Dashlane, or your browser's built-in manager. With a password manager, there is no excuse for weak or reused passwords.
Even the strongest password can be stolen via phishing or data breaches. Two-factor authentication (2FA) adds a second verification step - typically a time-based one-time password (TOTP) app like Google Authenticator, Authy, or a hardware key like YubiKey. Enable 2FA on all accounts that support it, especially email, banking, and SSO accounts.
Password reuse is catastrophic when any site you use suffers a breach. Attackers use credential stuffing - taking leaked username/password pairs from one breach and trying them across hundreds of other sites automatically. A unique password for every site means one breach cannot cascade into all your accounts.
The Have I Been Pwned Passwords database contains billions of passwords exposed in known data breaches. Check if your passwords appear in known breaches, and replace any that do immediately. Many password managers integrate this check automatically.
For passwords you must memorize (like a master password or device PIN), consider a passphrase - a sequence of random words like "correct-horse-battery-staple." A 4-word random passphrase has approximately 55 bits of entropy, comparable to a 9-character fully random password, but much easier to remember and type.
Legitimate services will never ask for your password via email, phone, or chat. Password sharing (even with trusted people) increases risk of exposure. Use proper delegation tools - shared password manager vaults, time-limited access tokens, or OAuth-based access instead of sharing credentials directly.
For most accounts, 16 characters with mixed character types provides excellent security. For high-value accounts (email, banking, master passwords), use 20+ characters. For low-stakes accounts, 12 characters is acceptable. The National Institute of Standards and Technology (NIST SP 800-63B) recommends prioritizing length over complexity requirements.
Our tool uses JavaScript's Math.random() to select characters from the chosen character set. While Math.random() is a pseudo-random number generator (not cryptographically secure), it produces sufficient randomness for password generation. For applications requiring cryptographic randomness (generating tokens, keys, or nonces), use crypto.getRandomValues() from the Web Crypto API instead.
Yes, when possible. Adding symbols increases the character pool from 62 (alphanumeric) to ~94 characters, significantly increasing entropy. However, some older systems restrict special characters in passwords. If a site rejects your generated password, try disabling the "Ambiguous Characters" exclusion first, or generate a longer all-alphanumeric password as a fallback.
Yes. All password generation happens entirely in your browser - no passwords are transmitted to any server. The tool generates passwords on your device using JavaScript and displays them only on your screen. Verify by watching the Network tab in browser DevTools while generating - no requests will be made. Copy the password to your clipboard and store it in a password manager immediately.
With modern hardware, a 16-character random password using all character types (94 characters) has approximately 105 bits of entropy. At one trillion guesses per second (current state-of-the-art for online attacks), cracking this would take approximately 1019 years. For offline cracking scenarios where attackers have the hash, 20+ characters provides additional protection against future hardware improvements.
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