Breakdown
How it works
Password strength is about length and character-set size: entropy = length × log₂(set size). 16 characters from all four sets is about 100 bits — uncrackable by brute force. Avoiding ambiguous characters (0/O, 1/l/I) helps when you must type it.
Formula
Worked example
16 characters with all sets (≈86 symbols): 103 bits — trillions of years at 10¹⁰ guesses per second.
Frequently asked questions
Is it safe to generate a password on a website?
This page generates it locally with window.crypto and sends nothing to any server; you can verify by loading the page and disconnecting from the internet.
How should I store passwords?
In a password manager (Bitwarden, 1Password, iCloud Keychain) with a long memorable master passphrase and two-factor authentication.
Passphrase or random string?
A 4–5 word random passphrase (e.g. correct-horse-battery-staple) is easier to type and remember with similar strength; use random strings where a manager fills them.