How to Create Strong, Secure Passwords (That Actually Hold Up)

A strong, secure password is at least 16 characters long, mixes uppercase letters, lowercase letters, numbers, and symbols, and is completely random — not built from words or phrases you know. That combination makes it practically impossible to crack with modern attack tools. Here's exactly how to create one, what mistakes to avoid, and how to check if your approach holds up.

What Makes a Password Strong and Secure?

Password strength comes down to two things: length and randomness. A longer password takes exponentially longer to brute-force (try every possible combination). Randomness means no attacker can predict it from a dictionary, a list of leaked passwords, or personal details about you.

• Length: 16+ characters is the current gold standard. Each extra character multiplies the difficulty enormously.
• Character variety: Mix uppercase (A–Z), lowercase (a–z), digits (0–9), and symbols (!@#$%^&*).
• True randomness: Not a favourite song lyric with a number on the end. Actual random generation.
• Uniqueness: One password per account. Reusing passwords is the single most common way accounts get compromised.

NIST (the US National Institute of Standards and Technology) updated its password guidelines in 2024 to emphasise length over complexity rules — a 20-character random passphrase beats a short, symbol-heavy string every time. You can read those guidelines on the NIST Identity and Access Management page.

How to Create Strong, Secure Passwords Step by Step

1. Use a random generator. Don't invent passwords yourself — humans are predictable. Use a tool that pulls from a cryptographically secure random source. Our free strong password generator does this in one click.
2. Set the length to 16 characters minimum. For financial accounts or email, go to 20+.
3. Enable all character types. Letters, numbers, and symbols together.
4. Copy it straight into a password manager. Never type it somewhere public first or email it to yourself.
5. Store it in a password manager like Bitwarden, 1Password, or the one built into your browser. You only need to remember one master password.
6. Enable two-factor authentication (2FA) on every account that offers it. A strong password plus 2FA means even a leaked password can't get someone in.

A Concrete Example: Generating a Secure Password in Python

If you're building an app and need to create passwords (or temporary credentials) programmatically, here's a minimal, correct approach in Python 3. It uses the secrets module — Python's cryptographically secure random generator, purpose-built for passwords and tokens.

# Python 3.6+
import secrets
import string

def generate_password(length=20):
    alphabet = string.ascii_letters + string.digits + '!@#$%^&*'
    # secrets.choice uses the OS's secure random source (not random.choice)
    return ''.join(secrets.choice(alphabet) for _ in range(length))

print(generate_password())
# Example output: G7!mXqP2#sLzR9vK&wYn

Never use Python's built-in random module for passwords — it's designed for simulations, not security. The secrets module is the right tool. See the official Python docs for secrets for more detail.

Common Mistakes That Weaken Your Passwords

Even people who think they're being careful often fall into these traps:

• Using personal information: Your name, birthday, pet's name, or favourite team. Attackers try these first.
• Simple substitutions: "P@ssw0rd" fools nobody. Automated cracking tools know every leet-speak variation.
• Reusing passwords across sites: When one site leaks your password (and they do), every account with that password is now open.
• Making it "memorable" at the cost of randomness: "SummerHoliday2023!" is 18 characters but trivially guessable.
• Storing passwords in plain text: A notes app, a spreadsheet, or a sticky note on your monitor. Use a proper password manager instead.
• Not updating after a breach: Check Have I Been Pwned to see if your email appears in a known data breach, and change any affected passwords immediately.

Passphrase vs. Random Password — Which Is Better?

A passphrase is four or more random words strung together — like correct-horse-battery-staple (famously illustrated by xkcd). A random character password is something like mR7!xQ9#pL2&vZ. Here's how they compare:

Type	Example	Memorability	Crack resistance	Best for
Passphrase (4 words)	tide-lamp-frost-rebel	High	Strong (if truly random words)	Master password for a password manager
Random character password (16+)	mR7!xQ9#pL2&vZ4@	Low	Very strong	Every other account (stored in a manager)

Use a long passphrase for the one password you must memorise — your password manager's master password. Use random character passwords for everything else, stored in the manager.

Tools That Make Creating Secure Passwords Instant

You don't have to think about all this every time. A good generator does the work for you:

• Password Generator: Creates cryptographically random passwords at any length, with full control over character types. The fastest way to get a strong password right now.
• Password managers (Bitwarden, 1Password, Dashlane): All include built-in generators and store your passwords safely, encrypted, and synced across devices.
• Hash Generator: If you're a developer storing passwords in a database, always hash them with a strong algorithm like bcrypt or Argon2 — not MD5 or SHA-1. Our hash tool supports SHA-256, which is useful for checksums and data integrity, though password hashing in applications needs bcrypt or Argon2, not a general-purpose hash.

Frequently Asked Questions About Strong, Secure Passwords

How long should a secure password be?

A secure password should be at least 16 characters for most accounts, and 20 or more for high-value accounts like email and banking. Length is the single biggest factor in crack resistance — every extra character multiplies the time needed to brute-force it by the size of the character set used.

Is it safe to use a password generator online?

Yes, as long as the generator runs in your browser (client-side) and doesn't send your password to any server. Reputable tools like our online password generator generate passwords locally in your browser — nothing is transmitted or stored. You can verify this by turning off your internet after the page loads and confirming the generator still works.

What is the difference between a strong password and a secure password?

Strong refers to how hard the password is to guess or crack — length, randomness, and character variety. Secure is broader: it includes how you store it, whether you reuse it, and whether you have 2FA on the account. A strong password used insecurely (reused, written on paper, stored in plain text) is not a secure one.

Should I change my passwords regularly?

NIST no longer recommends routine password changes on a fixed schedule. Change a password when there's a specific reason: a known breach, you suspect it was seen by someone else, or the service itself was compromised. Forcing frequent changes with no cause often leads to weaker passwords as people start making predictable patterns.