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🔐 Password Strength Checker & Generator

Generate strong, secure passwords with customisable options. Test any password's strength instantly.

1
Set your requirements
2
Generate password
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Copy and save securely
Generator Settings
Generated Password
Test Any Password

Password Security Best Practices

  • Use a minimum of 12 characters — 16+ is recommended for important accounts
  • Never reuse passwords across multiple sites — use a password manager like Bitwarden or 1Password
  • Enable two-factor authentication (2FA) on all important accounts especially banking and email
  • Change passwords immediately if you suspect a data breach — check haveibeenpwned.com
⏱️ Last Updated: June 2026 | MegaCalcOnline Editorial Team | Free browser-based tools — no upload required
🛡️ 100% Private
⚡ No Upload
💻 Browser-Based
🔒 Free Forever

🔑 Key Takeaways

  • Minimum 16 characters with all character types for important accounts (banking, email)
  • A passphrase (4+ random words) is both highly secure and memorable
  • Never reuse passwords across sites — use a password manager (Bitwarden is free)
  • Enable 2FA (two-factor authentication) on all critical accounts
  • Australian Cyber Security Centre (ACSC) recommends passphrases over complex short passwords

Password Generator & Strength Tester

Generate cryptographically secure passwords or test the strength of any existing password. The generator uses your browser's crypto.getRandomValues() API for true randomness — far stronger than Math.random(). All generation and testing happens in your browser with no data sent anywhere.

Password Strength Reference

TypeExampleCrack Time (2026)Rating
8 char, lower onlypasswordSeconds❌ Very Weak
8 char, mixedP@ss1234Hours⚠️ Weak
12 char, all typesX7@kL!p9qR2mYears✅ Good
16 char, all typesmK#9pQ2@vX!7wY4&Centuries✅ Strong
Passphrase (4 words)correct-horse-battery-stapleCenturies✅ Strong & Memorable
🔒 Security reminder: This generator runs in your browser and never sends passwords to MegaCalcOnline or any server. However, always store generated passwords in a reputable password manager (Bitwarden, 1Password, or your browser's built-in manager) — never in plain text files or notes.

Frequently Asked Questions

How does this password generator work?

The generator uses crypto.getRandomValues() — the browser's cryptographically secure random number generator — to select characters from your chosen character set. This is the same API used by security-critical applications, far more secure than standard Math.random().

What is two-factor authentication (2FA)?

2FA requires two proofs of identity: your password plus a second factor (usually a one-time code from an authenticator app like Google Authenticator or Microsoft Authenticator, or an SMS code). Even if your password is stolen, 2FA prevents unauthorised login. The Australian Cyber Security Centre strongly recommends enabling 2FA on all important accounts.

How many character types should a password include?

Use all four character types (uppercase, lowercase, numbers, symbols) for maximum security. At 16 characters with all types, brute-force cracking would take centuries with current hardware. Avoiding ambiguous characters (0, O, l, 1) with the 'Exclude ambiguous' option makes passwords easier to type manually.

Should I use a password manager?

Yes — strongly recommended. Password managers (Bitwarden is free and open-source; 1Password is popular) generate, store, and autofill unique strong passwords for every site. You only need to remember one strong master password. This is far more secure than reusing passwords or writing them in notes.