KeyGuard Pro: Free Password Generator & Strength Checker
KeyGuard Pro creates strong, random passwords and tells you how secure your existing passwords really are. Everything runs locally in your browser, so the passwords you generate or test are never sent to a server or stored anywhere.
What you can do with KeyGuard Pro
- Generate secure passwords with your choice of length, uppercase and lowercase letters, numbers and symbols.
- Check password strength in real time and see an estimate of its entropy as you type.
- Stay private. All processing is done on your device using your browser's built-in cryptographic random number generator.
- Use it for free, with no account or sign-up required.
How to create a strong password
The strength of a password comes mostly from its length and unpredictability. Longer passwords are exponentially harder to guess, and randomly generated ones avoid the patterns attackers look for.
- Use at least 14 to 16 characters for important accounts.
- Mix upper and lower case letters, numbers and symbols.
- Avoid names, birthdays, keyboard patterns and common words.
- Use a different password for every account.
- Store passwords in a reputable password manager instead of reusing them.
- Turn on two-factor authentication wherever it is offered.
Frequently asked questions
Is KeyGuard Pro safe to use?
Yes. Passwords are generated and analyzed entirely in your browser. Nothing you type or generate is transmitted or saved by KeyGuard Pro. The one exception is the optional Breach Check page, which sends only the first five characters of a one-way hash to the Have I Been Pwned service and compares the result on your device.
What is password entropy?
Entropy measures how unpredictable a password is, expressed in bits. The more bits of entropy, the more guesses an attacker needs to crack it.
How long should my password be?
For most accounts, 14 or more random characters is a good baseline. Use even longer passwords for email, banking and password manager master passwords.
How password strength is measured
KeyGuard Pro estimates strength as entropy, in bits. For a password made of randomly chosen characters, entropy is the password length multiplied by log2 of the size of the character set. Every extra bit doubles the number of guesses an attacker needs. The table below shows how quickly length and variety add up.
| Password | Entropy | Average time to guess |
|---|---|---|
| 8-digit PIN | 26.6 bits | Under a second |
| 4 random dictionary words | 51.7 bits | About 2 days |
| 12 random lowercase letters | 56.4 bits | About 55 days |
| 12 random letters and digits | 71.5 bits | About 5,000 years |
| 6 random dictionary words | 77.5 bits | About 350,000 years |
| 16 random characters, all types | 104.9 bits | Tens of trillions of years |
Times are an illustration, not a prediction. They assume an attacker who has stolen a fast-hashed password database and can test 10 billion guesses per second, and they use half the possible combinations as the average. Well-designed sites use slow hashing, which makes real attacks far slower, and passwords chosen by humans are much weaker than random ones of the same length.
Random passwords vs passphrases
A random string such as vK9#mQ2!xT7p packs a lot of entropy into few characters, but it is hard to type and remember. A passphrase made of several randomly chosen words is longer but easier to remember. Six words picked at random from a 7,776-word list reach about 77 bits, which is comparable to a 12-character password of random letters and digits.
What matters is that the choice is random. A phrase you made up yourself, a song lyric or a quote follows patterns that attackers test first, and it is far weaker than its length suggests.
How attackers guess passwords
- Credential stuffing: trying a password leaked from one site on many others. This is why every account needs its own password.
- Dictionary and rule attacks: testing common words with predictable changes such as "P@ssw0rd" or a trailing "1!".
- Brute force: trying every combination. Only long, random passwords hold up against it.
- Phishing: tricking you into typing a password on a fake page. No password strength can stop this, but two-factor authentication and passkeys help.
What KeyGuard Pro does not do
KeyGuard Pro does not store, sync or remember your passwords, so you must save each generated password yourself, ideally in a password manager. The strength score is an estimate based on length and character variety; it cannot know whether a password you chose has appeared in a data breach. If a site supports passkeys, they are usually safer than any password.