Free Password Generator

A password generator is a tool that creates strong, random passwords using a cryptographically secure source. Customize length and character types below, then copy passwords with one click. Everything runs in your browser - nothing is sent to a server.

Password Length20

4128

Character Types

Exclude ambiguous characters (0 O 1 l I | `)No repeating characters

Quantity (5)

Very Strong- 130.2 bits of entropy

Crack time: longer than the age of the universe

Crack time assumes an offline attacker at 10 billion guesses per second on average half of the keyspace.

How to use this password generator

Choose a password length using the slider. 16-20 characters is a good default for most accounts.
Select which character types to include: uppercase, lowercase, numbers, and symbols.
Optionally exclude ambiguous characters like 0, O, 1, l, and I to make passwords easier to read.
Click Generate to create a new batch of passwords using your browser's secure random source.
Click the copy button on any password to copy it to your clipboard, then paste it into the site or password manager you are setting up.

What makes a strong password?

The strength of a password is measured in bits of entropy. Each bit roughly doubles the work an attacker has to do. A password with 80 bits of entropy is considered strong; 100+ is very strong; anything below 40 bits is trivially breakable by modern hardware.

Three factors drive entropy:

Length - the dominant factor. Each extra character adds entropy equal to log2(charset size). For a 94-character keyboard set, that is ~6.5 bits per character.
Character variety - mixing uppercase, lowercase, digits, and symbols increases the per-character contribution.
True randomness - dictionary words, dates, and predictable substitutions (P@ssw0rd!) are guessed first by attackers and effectively cut entropy by orders of magnitude.

Frequently Asked Questions

What is the strongest password length?

For most accounts, 16-20 characters is considered strong. For sensitive accounts (banking, email, password vault) aim for 20+ characters. Anything 12 characters or shorter can be brute-forced if it lacks symbols or numbers. Longer is almost always better than complex - a 24-character random password is far stronger than an 8-character one with special tricks.

Are these passwords stored anywhere?

No. This password generator runs entirely in your browser using the Web Crypto API. Passwords are generated locally and never sent to a server, never logged, and never stored. Once you close the tab, they are gone.

How does this password generator work?

It uses crypto.getRandomValues(), the cryptographically secure random number generator built into your browser, to pick characters from your selected character set. Unlike Math.random(), this source is suitable for security-sensitive use and is the same primitive used by password managers and TLS implementations.

What characters should I include in a password?

Include uppercase letters, lowercase letters, numbers, and symbols if the site allows them. Each additional character class roughly doubles the work an attacker needs. If a site rejects symbols, compensate by adding length - a 24-character alphanumeric password is still extremely strong.

How often should I change my passwords?

Modern security guidance (NIST SP 800-63B) is to change passwords only when there is evidence of compromise, not on a forced schedule. Forced rotation tends to push people toward weaker, predictable passwords. Use a password manager, generate a unique strong password per site, and rotate only after a breach.

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