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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
3
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: August 2026 | Mohsin Iqbal | 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

What Is a Password Strength Checker?

A password strength checker analyses a password against the factors that actually determine how hard it is to crack: length, character variety (uppercase, lowercase, numbers, symbols), and whether it resembles a common or predictable pattern. This tool does both directions — generate a new cryptographically secure random password, or paste in an existing one to see its strength rating and estimated crack time.

Generated passwords use your browser's crypto.getRandomValues() API for true, cryptographically secure randomness — the same class of random number generator used in security-critical applications, and far stronger than the general-purpose Math.random() function.

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

How to Generate or Test a Password — Step by Step

  1. To generate: set your length and character type requirements, then click Generate
  2. Review the strength bar — aim for Strong or Very Strong for important accounts
  3. To test an existing password: paste it into the "Test Any Password" box for an instant rating and estimated crack time
  4. Copy and store the password in a reputable password manager — never in plain text

Who Uses This Tool

WhoCommon Use
🏢 Small business ownersGenerate strong, unique passwords for business accounts and shared logins
🔐 Anyone signing up for a new accountGenerate a strong password instead of reusing an old one
🧑‍💻 IT & support staffCheck whether a proposed password meets minimum strength requirements
🎓 Students & new usersUnderstand what actually makes a password strong or weak
🔍 Security-conscious usersTest an old, reused password to see how weak it really is
🔒 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.

What makes a password strong?

Length matters more than complexity: a 16+ character password using all four character types (uppercase, lowercase, numbers, symbols) is far stronger than an 8-character one with special characters crammed in. A long, random passphrase of unrelated words is both very strong and easier to remember than a short complex string.

How can I tell if my password has been compromised?

Check it against haveibeenpwned.com, which cross-references known data breaches without storing what you search. If a password shows up as compromised, change it immediately everywhere it's reused — that's also the strongest argument for never reusing passwords across sites.

What's a password strength checklist I can follow?

At minimum: 12+ characters (16+ for important accounts), a mix of uppercase, lowercase, numbers and symbols, no dictionary words or personal details, never reused across sites, and 2FA enabled wherever it's offered. This tool's strength bar checks most of these automatically as you type.

Is 8 characters long enough for a password?

Not for anything important. An 8-character password, even mixed case with numbers, can be cracked in hours with modern hardware. 12 characters is a reasonable minimum; 16+ with all character types is recommended for banking, email, and other high-value accounts.