Strong Password Generator
Unbreakable passwords in seconds. Pre-set to maximum security defaults.
What "Strong" Actually Means in 2026
Password strength isn't about complexity rules — it's about entropy. Entropy measures how unpredictable a password is, expressed in bits. Each bit doubles the number of possible combinations an attacker must try.
A password with 80+ bits of entropy is considered strong against current hardware. Our Strong Password Generator defaults to 20 characters with all character types, producing approximately 131 bits of entropy — well beyond what's needed for any current or foreseeable attack.
NIST SP 800-63B Guidelines
The National Institute of Standards and Technology updated its password guidelines with pragmatic, evidence-based recommendations:
- Minimum 8 characters (we recommend and default to 20)
- No composition rules — forcing "at least one uppercase" leads to predictable patterns like "Password1!"
- Screen against breached passwords — check your password against known leaks using our Leak Checker
- No forced rotation — changing passwords periodically leads to weaker passwords (users just increment a number)
- Support long passwords — services should accept at least 64 characters
Strength Comparison
| Category | Example | Entropy | Crack Time |
|---|---|---|---|
| Weak | password123 | ~20 bits | Instantly |
| Medium | Tr0ub4dor&3 | ~40 bits | ~3 hours |
| Strong | j7$Kp2!mNx#9qR4w | ~105 bits | ~billions of years |
| Unbreakable | aG#8kL!2pM$5nR@9wX&3 | ~131 bits | Heat death of universe |
Common Password Myths Debunked
Myth: Complex substitutions (@ for a, 3 for e) make passwords strong
Cracking tools have dictionaries with thousands of common substitutions built in. p@$$w0rd is cracked just as fast as password.
Myth: Adding a number at the end makes it secure
Attackers know this pattern. They try every dictionary word + 1, +2, +123, etc. This adds negligible entropy.
Myth: Changing your password frequently improves security
NIST explicitly discourages this. Users respond to forced rotation by making minimal changes (Password1 → Password2), which crackers exploit.
Frequently Asked Questions
What makes a password "strong"?
A strong password has high entropy — meaning it's unpredictable and resistant to all known attack methods. In practice, this means: 16+ characters, a mix of uppercase, lowercase, numbers, and symbols, no dictionary words, and no personal information. Our generator enforces all of these by default.
What does NIST recommend for password strength?
NIST Special Publication 800-63B (2024 revision) recommends: minimum 8 characters (we default to 16), no composition rules that reduce usability, checking against known breached passwords, and supporting up to 64+ characters. Notably, NIST no longer recommends forced periodic password changes.
How strong is a 16-character password with all character types?
A 16-character password using uppercase, lowercase, numbers, and symbols has approximately 105 bits of entropy. At 10 billion guesses per second (modern GPU cluster), it would take roughly 12.8 billion billion years to brute-force — far longer than the age of the universe.
Is a longer password always stronger?
Generally yes, but length alone isn't enough. A 30-character password of all "a"s has near-zero entropy. What matters is length combined with randomness. A truly random 16-character password with all character types is stronger than a 30-character password based on dictionary words.
Should I use a different strong password for every account?
Absolutely. Reusing passwords means one breach compromises all your accounts (credential stuffing). Use a password manager to store unique, strong passwords for every service. Your master password should be the strongest of all — consider a 20+ character passphrase.
How do I store strong passwords safely?
Use a reputable password manager like Bitwarden, 1Password, or KeePass. These encrypt your passwords with a master password and sync securely across devices. Never store passwords in plain text files, browser autofill without a master password, or sticky notes. For maximum security, you can also hash passwords with bcrypt if building your own system.