Password Generator – Strong Random Passwords

How to use the password generator

A new password is ready as soon as the page opens. To change it:

Set the length between 8 and 128 characters. Sixteen or more is a good default.
Choose which character types to include: uppercase letters, lowercase letters, digits and symbols.
Tick Exclude look-alike characters if you may need to read or type the password by hand. This removes O, 0, I, l and 1.
Press Generate again for a fresh password, then Copy to put it on your clipboard.

Your password stays on your device

The password is generated locally in your browser with the Web Crypto API. It is never sent to our server or anywhere else, and it is not stored. Once you close or reload the page it is gone, so save it in your password manager first.

How the password is built

The generator first picks one character from each type you selected, so every password contains at least one of each. The remaining positions are filled from the combined pool of allowed characters. Finally the characters are shuffled so the guaranteed ones do not sit in fixed places.

Random choices come from a cryptographically secure source. Numbers outside an exact multiple of the pool size are thrown away and drawn again, so every character is equally likely.

Strength and entropy

Entropy = Length × log2(Pool size), measured in bits. Each extra bit doubles the number of guesses an attacker would need.

Worked example

With all four types selected the pool has 90 characters. A 16-character password therefore has about 16 × log2(90) ≈ 104 bits of entropy, which is rated Very strong.

The labels used are: under 40 bits Weak, 40 to 59 Fair, 60 to 79 Strong, and 80 or more Very strong.

Good to know

Length matters more than complexity. Adding characters raises entropy faster than adding symbol types.
Use a different password for every account, and keep them in a password manager.
Some websites reject certain symbols. If that happens, turn symbols off and make the password a little longer.

Frequently asked questions

Is it safe to generate a password on a website?

With this tool, yes. The password is created in your own browser using its secure random number generator and is never transmitted or saved. You can even disconnect from the internet after the page loads and it will keep working.

How long should my password be?

At least 12 characters for everyday accounts, and 16 or more for important ones such as email, banking or your password manager. Longer is always stronger.

What does entropy in bits mean?

It measures how unpredictable the password is. A password with 80 bits of entropy would take on average 2 to the power of 79 guesses to find by brute force, which is far beyond what any attacker can try.

Why exclude look-alike characters?

Characters such as O and 0, or I, l and 1, are easy to confuse when a password is read aloud, printed or typed from another screen. Leaving them out avoids mistakes at the cost of a very small drop in entropy.

Why did the copy button not work?

Some browsers block clipboard access, for example in private windows or older versions. When that happens the password is selected for you, so you can copy it with Ctrl+C or Cmd+C.