Strong Password Generator
Generate cryptographically-strong passwords with custom length and character sets. Copy, download, and check entropy.
Passwords
—Copy—Copy—Copy—Copy—Copy—Copy—Copy—Copy—Copy—Copy
What is a Strong Password Generator?
A strong password generator creates random, unpredictable passwords using cryptographic algorithms. Unlike human-created passwords that often follow predictable patterns, generated passwords use true randomness to maximize security. This tool uses the Web Crypto API to generate cryptographically secure random values, ensuring your passwords are resistant to brute-force attacks, dictionary attacks, and pattern recognition.
Why You Need Strong Passwords
Weak passwords are the leading cause of data breaches and account compromises. Here's why strong, randomly generated passwords matter:
- Brute-force resistance: A 16-character password with mixed characters would take millions of years to crack with current computing power
- No personal patterns: Humans tend to use birthdates, names, and common words—hackers know this and exploit it
- Credential stuffing protection: Unique passwords for each account prevent one breach from compromising all your accounts
- Compliance requirements: Many organizations require passwords meeting specific complexity standards
How to Use This Password Generator
- Set password length: Choose between 4-128 characters (16+ recommended for high security)
- Select character types: Enable uppercase, lowercase, numbers, and symbols for maximum strength
- Configure options: Avoid ambiguous characters (O/0, l/1) for easier reading, require each type for guaranteed complexity
- Generate passwords: Create up to 50 passwords at once for multiple accounts
- Copy or download: Use individual copy buttons or download all passwords as a text file
Understanding Password Entropy
Entropy measures password strength in bits—the higher the entropy, the harder the password is to crack. Our generator displays real-time entropy calculations based on your settings:
Entropy Levels
- Below 40 bits: Very weak, easily cracked
- 40-64 bits: Weak, vulnerable to determined attacks
- 64-80 bits: Good for low-security accounts
- 80-128 bits: Strong, suitable for most purposes
- 128+ bits: Very strong, virtually uncrackable
Recommendations
- Email accounts: 80+ bits minimum
- Banking/Financial: 100+ bits recommended
- Master passwords: 128+ bits ideal
- Temporary accounts: 64+ bits acceptable
Password Security Best Practices
Do This
- Use a unique password for every account
- Store passwords in a reputable password manager
- Enable two-factor authentication (2FA) when available
- Use at least 16 characters for important accounts
- Regenerate passwords periodically for sensitive accounts
Avoid This
- Never reuse passwords across multiple sites
- Don't use personal information in passwords
- Avoid common substitutions (@ for a, 3 for e)
- Don't store passwords in plain text files
- Never share passwords via email or text
Features of This Password Generator
- Cryptographically secure: Uses the Web Crypto API for true randomness, not pseudo-random algorithms
- Customizable length: Generate passwords from 4 to 128 characters
- Character set control: Choose exactly which character types to include
- Ambiguous character filtering: Remove confusing characters like O/0 and l/1/I
- Guaranteed complexity: Option to require at least one character from each selected type
- Bulk generation: Create up to 50 passwords simultaneously
- Real-time entropy display: See exactly how strong your password configuration is
- One-click copy: Instantly copy individual passwords or all at once
- Download option: Save generated passwords to a text file
- Privacy-focused: All generation happens in your browser—nothing is sent to any server
Frequently Asked Questions
Are these passwords truly random?
Yes. This generator uses the Web Crypto API (crypto.getRandomValues), which provides cryptographically secure pseudorandom numbers. This is the same level of randomness used by security professionals and meets NIST standards.
Is it safe to generate passwords online?
With this tool, yes. All password generation happens entirely in your browser using JavaScript. No passwords are ever transmitted to any server, stored in any database, or logged anywhere. You can verify this by using the tool offline after the page loads.
How long should my password be?
For most accounts, 16 characters is a good minimum. For high-security accounts (banking, primary email, password manager master password), aim for 20-24 characters or more. The entropy meter helps you gauge strength.
Should I use all character types?
Generally yes—more character types increase entropy. However, some systems have restrictions. If a site doesn't accept symbols, disable them. The "Require each type" option ensures your password contains at least one character from each enabled category.
What does "Avoid ambiguous characters" mean?
This option removes characters that look similar in many fonts: uppercase O and zero (O/0), lowercase L and one (l/1), uppercase I and lowercase l (I/l), etc. This makes passwords easier to read and type manually when needed.
How do I remember these random passwords?
You don't need to memorize them. Use a password manager like Bitwarden, 1Password, or KeePass to securely store all your passwords. You only need to remember one strong master password for your password manager.