Password Generator
Create Strong & Secure Passwords Instantly
What Makes a Password Actually Strong?
A password's strength comes down to one number: entropy, measured in bits. Entropy is a measure of how many guesses an attacker would need, on average, to find your password by brute force. Every character you add, and every additional character type you include (lowercase, uppercase, digits, symbols), multiplies the total number of possible combinations — which is why length and variety matter far more than clever substitutions like swapping "a" for "@". A random 8-character password using only lowercase letters has about 37 bits of entropy. A random 16-character password using all four character types has over 100 bits — the difference between a password crackable in hours and one that would take longer than the age of the universe with current hardware.
This tool generates passwords using your browser's cryptographic random number source, combining the character sets you select to maximize entropy for the length you choose. Nothing is predictable or pattern-based — every character is selected independently, which is exactly what makes a password resistant to both guessing and automated cracking tools.
How Long Would It Take to Crack Your Password?
The table below shows rough brute-force cracking times for different password lengths and character sets, based on a modern offline attack rate of roughly 10 billion guesses per second — a realistic figure for an attacker using consumer GPU hardware against a leaked password hash.
| Length | Lowercase Only | Upper + Lower + Numbers | All Characters + Symbols |
|---|---|---|---|
| 8 characters | 5 hours | 8 days | 3 months |
| 10 characters | 3 months | 6 years | 44 years |
| 12 characters | 3 years | 34,000 years | 2 million years |
| 16 characters | 9,000 years | 1 billion years | practically uncrackable |
These are averages for a single offline brute-force attempt, not guarantees — a password could theoretically be guessed on the first try, or take twice as long. The point is the order of magnitude: a 16-character password with mixed character types is not just "a bit better" than an 8-character one, it is millions of times harder to crack.
Password Generator Options Explained
1. Password Length
Length is the single biggest factor in password strength. Every extra character multiplies the total number of possible combinations by the size of your character set. Security researchers and organizations like NIST now recommend a minimum of 12 characters for important accounts, with 16 or more for anything protecting financial data, email, or password managers themselves.
2. Uppercase Letters (A–Z)
Adds 26 possible characters per position. Mixing case is a cheap way to multiply entropy without adding length, since most sites still accept it universally.
3. Lowercase Letters (a–z)
The base character set for most passwords and the one every site accepts. On its own it is the weakest option — always combine it with at least one other character type.
4. Numbers (0–9)
Adds 10 more possible characters per position. Avoid predictable placements like years, birthdays, or sequences (123, 2024) — a generated password places digits randomly throughout the string, not just at the end.
5. Symbols (!@#$%^&*)
Symbols add the largest character set per position and are required by most banking and enterprise login systems. Some older or poorly built sites still reject certain symbols — if your generated password gets rejected, regenerate with only letters and numbers enabled.
Common Password Mistakes That Undo Strong Generation
- Reusing the same password across sites. If one service you use is breached — and data breaches happen constantly — attackers immediately try that same password on your email, banking, and social accounts. This single habit causes more account takeovers than weak passwords do.
- Using personal information (names, birthdays, pet names). These are the first guesses in any targeted attack and are often public on social media.
- Predictable substitutions. Replacing "a" with "@" or "e" with "3" (leetspeak) adds almost no real entropy — cracking tools have included these substitutions in their dictionaries for over a decade.
- Storing passwords in plain text. A note on your phone, a spreadsheet, or a sticky note is only as secure as whoever else can access that device. Use a dedicated password manager instead — see below.
- Never rotating breached passwords. If a service you use announces a breach, change that password immediately, and change it everywhere else you reused it.
Where to Store the Passwords You Generate
A truly random, unique 16-character password is impossible to memorize for every account — and that's fine. The correct approach isn't to memorize dozens of strong passwords, it's to use a password manager (Bitwarden, 1Password, and your browser's built-in manager are all reasonable choices) to store them, and memorize only one strong master password to unlock the manager itself. Generate a new password with this tool for each account, save it directly into your password manager, and let autofill handle the rest. This is the single most effective practical change most people can make to their account security.
Wherever a service offers it, enable two-factor authentication (2FA) in addition to a strong password. 2FA means that even if a password is somehow compromised, an attacker still needs a second factor — a code from your phone or an authenticator app — to get in. Password strength and 2FA solve different problems and work best together.