Password Security for Vibe Coders: Building Secure Authentication
Using Supabase Auth or Firebase? Good choice. But are you making your users use strong passwords? And what about your own accounts? Let's talk password security.
The Two Sides of Password Security
As a vibe coder, you need to think about passwords in two contexts:
Your Own Passwords
The passwords you use for GitHub, Vercel, Supabase, Stripe, and all the services that power your app. If these get compromised, attackers own your infrastructure.
Your Users' Passwords
The passwords your users create for your app. If you allow weak passwords, your users are at risk—and so is your reputation when they get hacked.
What Makes a Password Strong?
Password strength comes down to one thing: how long it takes to guess. This depends on:
1. Length (Most Important)
Every additional character exponentially increases the number of possible combinations. A 16-character password is vastly stronger than an 8-character one with "complex" requirements.
2. Character Variety
Using uppercase, lowercase, numbers, and symbols increases the character set size. But length matters more—"correcthorsebatterystaple" beats "P@ssw0rd!"
3. Randomness
Attackers use dictionaries of common passwords and patterns. "password123!" and "qwerty2024" are in every wordlist. True randomness is key.
Test your password strength with our free Password Strength Checker—it runs entirely in your browser, so your password never leaves your device.
The Vibe Coder's Personal Security Stack
Here's how to secure your own accounts—the ones that control your entire infrastructure:
Use a Password Manager
1Password, Bitwarden (free), or Apple Keychain. Generate a unique 20+ character password for every service. You only need to remember one master password.
Enable 2FA on Everything
Use an authenticator app (not SMS). Prioritize: GitHub, your email, Vercel/hosting, Supabase/Firebase, domain registrar, Stripe.
Use Hardware Keys for Critical Accounts
YubiKey or similar for GitHub, Google, and AWS. Hardware keys are phishing-proof—they verify the actual domain, not just a code.
Check for Breaches
Use our Data Breach Checker to see if your email has appeared in any breaches. If it has, change those passwords immediately.
Protecting Your Users
If you're using Supabase Auth or Firebase Auth, password hashing is handled for you. But you still need to think about password policies.
Password Requirements: The Right Way
Minimum 12 characters - Length is the most important factor
Check against breach databases - Block passwords that have been exposed in breaches
Show password strength meter - Help users understand how strong their password is
Encourage passphrases - "correct-horse-battery-staple" is easier to remember than "P@ssw0rd!"
What NOT to Do
Don't require specific character types - "Must have uppercase, number, and symbol" leads to Password1!
Don't force periodic password changes - This leads to password1, password2, password3...
Don't set a maximum length - Let users use long passphrases if they want
Don't block paste - Users should be able to paste from password managers
Implementing in Supabase
Supabase handles password hashing with bcrypt. To add custom validation:
// Client-side validation before signup
function validatePassword(password) {
const errors = [];
if (password.length < 12) {
errors.push('Password must be at least 12 characters');
}
// Check against common passwords
const commonPasswords = ['password123', 'qwerty123', ...];
if (commonPasswords.includes(password.toLowerCase())) {
errors.push('This password is too common');
}
return errors;
}
// Then signup
const { error } = await supabase.auth.signUp({
email,
password,
});Implementing in Firebase
Firebase Auth also handles hashing. Add client-side validation:
// Validate before createUserWithEmailAndPassword
import { createUserWithEmailAndPassword } from 'firebase/auth';
const errors = validatePassword(password);
if (errors.length > 0) {
throw new Error(errors.join(', '));
}
await createUserWithEmailAndPassword(auth, email, password);Bonus: Checking Breached Passwords
The HIBP Pwned Passwords API lets you check if a password has been exposed in a breach, without sending the actual password. It uses k-anonymity:
// Check if password is breached (client-side safe)
async function isPasswordBreached(password) {
const hash = await sha1(password);
const prefix = hash.substring(0, 5);
const suffix = hash.substring(5).toUpperCase();
const response = await fetch(
`https://api.pwnedpasswords.com/range/${prefix}`
);
const text = await response.text();
return text.includes(suffix);
}This sends only the first 5 characters of the SHA-1 hash, so HIBP never sees the actual password. If the password is breached, block it.
Key Takeaways
Use a password manager and unique passwords for all your developer accounts
Enable 2FA on everything, hardware keys for critical accounts
For your users: prioritize length over complexity requirements
Check passwords against breach databases before accepting them
Let Supabase/Firebase handle the hashing—focus on policies and 2FA
Test Your Password Strength
Our free tool analyzes your password locally—it never leaves your browser.
Scan Your App's Security
VAS checks for auth vulnerabilities, exposed tokens, and insecure configurations.