Every day, millions of accounts are compromised because people use weak, guessable, or reused passwords. Yet creating a truly strong password is simpler than most people think — once you understand what "strong" actually means.
What Makes a Password Truly Strong?
A strong password has three core properties:
- Length: The longer the password, the exponentially harder it is to crack.
- Randomness: It must not contain predictable patterns, words, dates, or keyboard sequences.
- Uniqueness: It must be used for exactly one account — never reused.
The Math Behind Password Strength (Entropy)
Password strength is measured in bits of entropy. The formula is simple:
Where H is entropy in bits, L is password length, and N is the size of the character pool (e.g., 94 for all printable ASCII).
Here's what different entropy levels mean in practice, assuming 1 trillion guesses per second (a fast offline attack):
Step-by-Step: Creating a Strong Password
Step 1: Choose Your Length
Start with a minimum of 16 characters for regular accounts. For email, banking, and social media — use 20 or more. For encrypted backups and master passwords, use 24+.
Step 2: Use All Character Types
Enable all four character sets for maximum security:
- ✅ Uppercase letters (A–Z): 26 characters
- ✅ Lowercase letters (a–z): 26 characters
- ✅ Numbers (0–9): 10 characters
- ✅ Symbols (!@#$%^&*...): 32+ characters
Using all four gives you a pool of 94 characters, compared to just 26 for lowercase only. A 16-character password goes from 75 bits to 105 bits of entropy just by adding all character types.
Step 3: Let a Tool Generate It
Human brains are terrible at creating random passwords. We unconsciously introduce patterns — our birth year, our cat's name, keyboard walks like "qwerty123". The only way to get true randomness is to let a cryptographically secure tool do it.
Use a password generator that uses crypto.getRandomValues(), not Math.random(). The former is a true CSPRNG (Cryptographically Secure Pseudo-Random Number Generator); the latter is not safe for security purposes.
Step 4: Store It in a Password Manager
A strong password that you can't remember is perfectly fine — that's what password managers are for. Options include Bitwarden (free, open-source), 1Password, and KeePassXC (offline). Never write passwords on paper or in a notes app.
Passwords to Absolutely Avoid
- ❌ Any word found in a dictionary (sunshine, dragon, master)
- ❌ Names of people, pets, places, or sports teams
- ❌ Birth dates, anniversaries, phone numbers
- ❌ Keyboard patterns: qwerty, 123456, asdfgh
- ❌ Anything you've used before on another site
- ❌ The word "password" in any variation
Quick Reference: Password Length vs Strength
The Bottom Line
Creating a strong password takes about 5 seconds with the right tool. There is no excuse for a weak password in 2025 — especially when free, private, client-side generators exist. Generate yours now, store it in a password manager, and never think about it again.