Password Generator Online — Create Strong Random Passwords Free

Password Strength by Length and Character Set

How to Use the Password Generator

1. Open the password generator.
2. Set the length. Use the slider to choose password length. 16 characters minimum for most accounts; 20+ for financial, email, and admin accounts.
3. Choose character sets. Toggle uppercase (A–Z), lowercase (a–z), numbers (0–9), and symbols (!@#$%^&*). Include all four for maximum strength unless the service has restrictions.
4. Generate. Click Generate to create a new random password. Click again to regenerate.
5. Copy and save. Copy and immediately paste into your password manager. Do not save in plain text documents or emails.

What Makes a Password Strong

Password strength is measured by entropy — the number of possible combinations an attacker must try to guess the password by brute force. Entropy is calculated as: bits = log₂(character_set_size^length) = length × log₂(character_set_size).

Practical implications:

• A 16-character lowercase-only password has 26¹⁶ ≈ 4.4 × 10²² combinations — more than sufficient
• An 8-character full-character-set password has 95⁸ ≈ 6.6 × 10¹⁵ combinations — crackable in hours with modern hardware
• Length multiplies entropy linearly; adding character types multiplies it logarithmically
• The practical lesson: length is more important than complexity — a 20-character lowercase random string beats a 10-character complex password

Common Password Mistakes

Passphrases vs. Random Character Passwords

A passphrase is a sequence of random words: correct-horse-battery-staple, violet-lamp-seven-ocean-table. Advantages:

• Memorable without writing down: 4–5 random words are much easier to recall than r8#Kz!mQxL
• High entropy: 5 random words from a 7,776-word diceware list = 7,776⁵ combinations ≈ 2.8 × 10¹⁹ — more secure than most character-based passwords of moderate length
• Resistant to keyboard walk attacks: Patterns like qwerty123, asdfghjk are in every attacker dictionary; random words are not
• Better for master passwords: Your password manager master password should be a passphrase you can type from memory — use 6–7 words for excellent security

The recommendation: use random character passwords (generated here) for regular accounts stored in your password manager; use a passphrase for your password manager master password and any other password you must memorise.

Using a Password Manager

You cannot memorise 50+ unique 20-character passwords. A password manager solves this:

• Bitwarden (free): Open-source, cloud-sync, audited. Free tier covers unlimited passwords across devices. One of the most recommended managers.
• 1Password: Excellent UX; family and team sharing; Travel Mode. Subscription-based.
• KeePass (free): Open-source, local storage only (you control your data). No cloud sync by default.
• Apple Keychain / Google Password Manager: Built into iOS/macOS and Android/Chrome. Good for users within those ecosystems. Less portable.

A good password manager:

• Generates strong passwords for new accounts
• Autofills on login — no typing, resistant to keyloggers
• Flags reused and weak passwords in your vault
• Alerts you when sites you use are breached (Have I Been Pwned integration)
• Works across all your devices

The password strength checker can help you audit existing passwords to find weak or reused ones before migrating to a manager.

Two-Factor Authentication: The Second Layer

Even the strongest password can be phished or stolen in a data breach. Two-factor authentication (2FA) adds a second verification step that attackers cannot use without your physical device:

• TOTP authenticator apps: Google Authenticator, Authy, Microsoft Authenticator. 6-digit codes that change every 30 seconds. Much more secure than SMS codes.
• Hardware security keys (FIDO2/U2F): YubiKey, Google Titan Key. Physical device that must be present. Most secure option — resistant to phishing.
• SMS / email 2FA: Better than nothing but weakest form — SIM swapping attacks can bypass SMS codes.
• Passkeys: The emerging replacement for passwords — cryptographic key pairs stored on device; phishing-proof; supported by Apple, Google, Microsoft, and major sites.

Enable 2FA on: email accounts (highest priority — email is the recovery method for everything else), banking and financial accounts, password manager, social media, and any account storing sensitive data.

NIST Password Guidance: What Security Agencies Now Recommend

NIST SP 800-63B (the US standard for digital identity authentication) revised password guidance based on research into actual attacker behaviour:

• Do not require periodic password changes unless there is evidence of compromise — forced rotation leads to weaker passwords (password1 → password2)
• Do not require complex composition rules (e.g., must contain uppercase, number, symbol) — these produce predictable patterns (Password1!, Welcome2024) rather than genuine randomness
• Do require minimum 8 characters — ideally support longer passwords up to 64+ characters
• Check against known compromised passwords — reject passwords found in breach databases (e.g., "123456", "password")
• Allow all printable characters including spaces (for passphrases) — do not arbitrarily restrict character sets

The practical implication: a long, randomly generated password that never changes is more secure than a moderately complex password changed every 90 days.

Common Questions

Is it safe to generate passwords in a browser?

This generator uses the Web Cryptography API (window.crypto.getRandomValues()) — the browser's built-in cryptographically secure random number generator. The password is generated entirely locally in your browser and is never transmitted to any server. It is safe to use on a trusted device on a trusted network. The generator has no server-side component, no analytics tracking of passwords, and no logging.

Should I avoid certain characters?

Some websites reject certain special characters — particularly quotes (' "), backslashes (\), angle brackets (< >), or non-ASCII characters. If a generated password is rejected at signup, regenerate without symbols or toggle only safe symbols (!@#$%^&*). Most reputable services accept all printable ASCII characters — poor character restrictions are a sign of weak input sanitisation, which is itself a security concern.

How often should I change my password?

Per NIST SP 800-63B: change a password when (1) you know or suspect it has been compromised, (2) the service reports a data breach affecting your account, (3) you have shared it with someone who no longer needs access, or (4) it is weak or reused and you are migrating to a manager. Do not change passwords on a fixed schedule without these triggers — routine rotation without cause produces weaker passwords, not stronger ones.