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DayUtils

Password Generator – Strong Random Passwords

Create strong, random passwords with the length and characters you choose. Passwords are made on your device with your browser’s secure random generator and are never sent anywhere.

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How to use the password generator

  1. Set the length with the slider (or type a number up to 128).
  2. Choose which characters to include: lowercase, uppercase, numbers and symbols.
  3. Optional: turn on Avoid look-alike characters if you will type the password by hand.
  4. Check the strength meter, then tap Copy.
  5. Tap New password for another one. Save it in your password manager straight away.

How the passwords are made

Each character is chosen at random from the sets you selected, using your browser’s cryptographically secure random number generator — the same kind used for encryption. We never use Math.random(), which is not secure.

To keep the choice fair, the tool uses rejection sampling, so every character has exactly the same chance of being picked. It also makes sure at least one character from each selected set appears, then shuffles the result so those characters are not always at the start.

How strength is worked out

Strength in bits = length × log2(number of possible characters)

For example, a 16-character password using letters, numbers and 25 symbols has about 103 bits of randomness. Even an attacker trying billions of guesses a second would need far longer than a lifetime to work through that many possibilities. An 8-character password with only lowercase letters and numbers has about 41 bits, which modern computers can crack much faster.

Good password habits

  • One account, one password. Never reuse passwords, especially for email and banking.
  • Use a password manager. Most phones and browsers have one built in.
  • Turn on two-factor authentication (2FA) with an authenticator app or SMS for important accounts.
  • Never share OTPs or passwords on calls or messages. Banks and government offices never ask for them.
  • Change a password straight away if you hear a service you use has been hacked.

Who uses a password generator

  • Anyone creating a new account — email, banking, shopping or social media.
  • Families setting a strong Wi-Fi password (then share it easily with a Wi-Fi QR code).
  • Small offices setting up accounts for new staff.
  • Developers creating test credentials and API secrets.

Because the password exists only on your screen, nobody else — including us — ever sees it.

Frequently asked questions

Is it safe to generate a password on a website?

Here, yes: the password is created by your own browser using its cryptographic random number generator (crypto.getRandomValues). It is not sent to any server, stored or logged. You can even switch off your internet after the page loads and it still works.

How long should my password be?

For important accounts like email and banking, use at least 12 characters with a mix of letters, numbers and symbols — 16 or more is better. Length adds more strength than complexity alone.

What does the strength meter measure?

It estimates entropy — how many random guesses an attacker would need — from the length and the number of possible characters. Because the password is truly random, this estimate is accurate. Around 60 bits is strong and 80+ bits is very strong.

Why avoid look-alike characters?

Characters like l, I, 1, O and 0 are easy to confuse when you have to type a password from paper or read it out. Leaving them out makes the password easier to use with only a small loss of strength.

How do I remember strong passwords?

Don’t try to remember dozens of them. Use a password manager, which stores them securely and fills them in for you. Remember one strong master password, and turn on two-factor authentication for important accounts.

Should I use the same password for many accounts?

No. If one website is hacked, attackers try the same email and password on other sites. A unique password for every account stops one leak from opening all your accounts.

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