Password Generator

How password attacks actually work

Understanding how passwords get broken is the fastest way to understand what makes a good one. Attackers almost never sit at a login screen typing guesses — they work offline, at enormous speed, against stolen data.

Brute force means trying every possible combination of characters. A modern graphics card can test tens of billions of guesses per second against a leaked password database. Short passwords fall in seconds; this is why length matters more than anything else.

Dictionary and rule-based attacks don't try random strings — they try real words, names, dates, and predictable substitutions like "P@ssw0rd!" first. Anything based on a word, however cleverly disguised, is checked early. A truly random string has no pattern to exploit, so it gains no protection-penalty here.

Credential stuffing is the most common real-world attack today. When one site is breached, attackers take those email-and-password pairs and try them automatically on hundreds of other services. It works only because people reuse passwords — which is why a unique password per site matters as much as strength.

Phishing sidesteps cracking entirely by tricking you into typing your password into a fake page. No password is strong enough to survive being handed over, which is why two-factor authentication (below) is such an important backstop.

What actually makes a password strong

The single most important property is length. Every character you add multiplies the number of possible combinations, so a long password becomes exponentially harder to brute-force. A 16-character random password is dramatically stronger than an 8-character one — not twice as strong, but billions of times stronger.

The second property is randomness. Security is measured in "entropy" — essentially, how unpredictable the password is, expressed in bits. Each bit doubles the work an attacker must do. A password drawn randomly from all four character types carries far more entropy per character than a memorable phrase you invented, because there is no underlying pattern to guess. This generator reports the exact entropy and an estimated crack time for every password it creates.

A common myth is that swapping letters for symbols ("e"→"3", "a"→"@") makes a weak password strong. It barely helps, because attackers' cracking rules already know every common substitution. Genuine randomness is what counts.

Passphrases — four or more random, unrelated words like "harbor-violet-engine-cactus" — are a strong, memorable alternative for the handful of passwords you must type by hand, such as your device login or password-manager master password. For everything else, a long random string stored in a manager is ideal.

Protecting your accounts beyond the password

A strong, unique password is the foundation, but a few habits multiply your security:

Use a password manager. It's impossible to remember a different 16-character random password for every account, and you shouldn't try. A reputable manager (Bitwarden, 1Password, or the one built into your browser) generates, stores, and autofills them, so the only password you ever memorize is the one that unlocks the vault. Make that one a long passphrase.

Turn on two-factor authentication (2FA). This requires a second proof of identity — a code from an authenticator app, a hardware key, or a prompt on your phone — in addition to your password. Even if a password is stolen or phished, 2FA usually stops the attacker cold. App-based or hardware 2FA is more secure than SMS codes.

Keep every password unique. Reuse is the vulnerability that credential-stuffing attacks depend on. If each account has its own password, a breach at one service can't cascade into the others.

Respond quickly to breaches. If a service you use is breached, change that password immediately — and any other account where you reused it. Services like Have I Been Pwned let you check whether your email has appeared in a known breach.

Frequently Asked Questions