Password Generator
Create strong, secure passwords instantly
Character Set
About Password Generator
This tool helps you create strong, secure passwords that are difficult to crack. Strong passwords are essential for protecting your online accounts and personal information.
Tips for Strong Passwords
- Use at least 12-16 characters for better security
- Include a mix of uppercase, lowercase, digits, and symbols
- Avoid using personal information like birthdays or names
- Use different passwords for different accounts
- Consider using a password manager to store your passwords securely
About Passphrases
Passphrases are passwords made up of random words. They are easier to remember but still very secure due to their length. A passphrase like 'correct-horse-battery-staple' can be more secure than a short complex password.
Understanding Password Strength
Password strength is calculated based on the character set size and password length. The crack time estimation assumes an attacker using a fast computer capable of billions of guesses per second.
Password Entropy by Length & Character Set
Entropy (bits) determines password strength. Higher entropy = harder to crack. 80+ bits recommended for sensitive accounts.
| Character Set | 8 | 10 | 12 | 16 | 20 |
|---|---|---|---|---|---|
| Digits only (0-9) | 27 bits | 33 bits | 40 bits | 53 bits | 66 bits |
| Lowercase (a-z) | 38 bits | 47 bits | 56 bits | 75 bits | 94 bits |
| Mixed case (a-z, A-Z) | 46 bits | 57 bits | 68 bits | 91 bits | 114 bits |
| Alphanumeric (a-z, A-Z, 0-9) | 48 bits | 60 bits | 71 bits | 95 bits | 119 bits |
| Full (letters + digits + symbols) | 52 bits | 66 bits | 79 bits | 105 bits | 131 bits |
Password Strength for Common Encryption Algorithms
| Algorithm | Key Size | Min Password (full charset) | Recommendation |
|---|---|---|---|
| AES-128 | 128 bits | 20 chars | 16+ chars with full charset for standard security |
| AES-256 | 256 bits | 39 chars | 24+ chars recommended, 39+ for maximum security |
| RSA-2048 | ~112 bits | 17 chars | Standard for certificates, 16+ chars sufficient |
| RSA-4096 | ~140 bits | 22 chars | High security scenarios, 20+ chars recommended |
| SHA-256 | 256 bits | 39 chars | For password hashing, use with salt and iterations |
| bcrypt | 184 bits | 28 chars | Preferred for password storage, built-in salt |
* Minimum password length assumes full character set (95 printable ASCII). Using fewer character types requires longer passwords.
Security Note
All passwords are generated locally in your browser using cryptographically secure random number generation. No passwords are sent to any server or stored anywhere.
Frequently Asked Questions
How long should a secure password be?
Current guidelines from NIST and security researchers recommend at least 12 characters, with 16 or more being ideal for sensitive accounts. Length matters more than complexity: a 20-character password made of random words is stronger than an 8-character mix of symbols. Many modern systems also allow passphrases — sequences of random words — which are both strong and memorable.
What makes a password truly random?
A truly random password is generated by a cryptographically secure pseudo-random number generator (CSPRNG), not by predictable patterns like replacing letters with numbers. This generator uses window.crypto.getRandomValues(), which is backed by your operating system's entropy source. Avoid password generators that run server-side, as you cannot verify whether they log your passwords.
Should I include symbols in my password?
Symbols increase the character set size, which raises the number of possible combinations. However, some sites restrict which symbols are allowed, and a longer password without symbols can be stronger than a shorter one with them. The most important factors are randomness and length. If symbols are allowed, including them provides a modest additional layer of strength.
Is it safe to use a password manager?
Yes — using a reputable password manager (such as Bitwarden, 1Password, or KeePass) is strongly recommended by security professionals. It lets you use a unique, long, random password for every account without needing to memorize them. The master password should be strong and stored in your memory. The risk of reusing passwords across sites far exceeds the risk of a well-audited password manager being compromised.
What is entropy and why does it matter for passwords?
Password entropy measures unpredictability in bits. Each additional bit of entropy doubles the number of possible guesses an attacker needs. A password from a 94-character set with 16 characters has about 105 bits of entropy — far beyond what any brute-force attack could exhaust. Low-entropy passwords (like common words or patterns) can be cracked in seconds with modern GPUs and dictionary attacks.
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