How to Tell If a Password Is Actually Strong (Not Just Long)

"Use a longer password" is decent advice that people follow in the least useful way possible — Password12345678 is 16 characters long and still weak, because length only helps if it comes with unpredictability. What actually matters is entropy: how many guesses an attacker would need before landing on your password, assuming they know your general strategy.

Generate, don't invent

The reliable way to get a genuinely strong password is to not think one up yourself. Human-invented passwords cluster around predictable patterns — a word, a number, a symbol tacked on the end — because that's how memory works. A Password Generator with a large enough character set and length sidesteps this entirely by picking randomly, which is precisely the thing brains are bad at doing on purpose.

For anything that goes in a password manager anyway (which should be almost everything), there's no cost to maximizing length and character variety — you're not going to type it from memory.

Measure it instead of guessing

Rather than trusting a strength meter's red/yellow/green bar, it's worth understanding what you're actually looking at. The Password Strength Checker estimates entropy and an approximate crack time, and gives specific feedback on what's weakening a given password — a repeated pattern, a dictionary word, insufficient length for the character set used.

The concrete number matters more than the color. "68 bits of entropy" tells you something; "this bar is orange" doesn't.

Where hashing fits in

Password generation and password hashing are different problems that get conflated a lot. A generator makes a strong secret; a hash is what you'd compare against if you were storing a way to verify a password without storing the password itself. If you're building anything that needs to verify credentials, never store a password directly — the Hash Generator is useful for understanding what SHA-256 output looks like and how hashing behaves, but production authentication should use a purpose-built password hashing algorithm (bcrypt, scrypt, or Argon2), not a general-purpose hash function like SHA-256 on its own — general hash functions are fast by design, which is exactly the wrong property for hashing something an attacker might try to brute-force.

The actual habit worth building

Use a password manager, generate a unique random password per site, and stop trying to make passwords memorable — that's what the manager is for. The only password worth memorizing is the one that unlocks the manager itself, and that one is worth spending real effort on: long, random, and not reused anywhere else.