How to use Password Generator
Generate strong, random passwords instantly in your browser — no data is ever sent to a server. Choose length, character sets (uppercase, lowercase, numbers, symbols), and exclude ambiguous characters. Use the built-in strength meter to verify entropy before copying. Essential for creating secure logins, API keys, database credentials, and any account that handles sensitive data.
- Set the desired password length (12–20 characters is recommended for most accounts; 24+ for privileged access).
- Select character sets: uppercase letters, lowercase letters, numbers, and special symbols.
- Toggle "exclude ambiguous characters" to avoid look-alike chars like 0/O and l/1/I.
- Click Generate to create a new password and review the strength indicator.
- Click Copy to copy the password to your clipboard and paste it into your password manager.
Your data never leaves your device — 100% private processing.
Password strength and entropy
Password strength is measured in bits of entropy — the logarithm (base 2) of the total number of possible combinations. An 8-character password using only lowercase letters has 26^8 ≈ 200 billion combinations (37 bits of entropy), crackable in hours with modern hardware. A 16-character password using all character sets has 95^16 ≈ 4×10^31 combinations (105 bits), which would take billions of years to brute-force. NIST SP 800-63B recommends at least 8 characters, but 12–16+ is the practical minimum for 2024 threat models.
| Length | Character set | Entropy (bits) | Crack time (estimate) |
|---|---|---|---|
| 8 | Lowercase only | 37 | Hours (GPU cluster) |
| 12 | Lowercase + numbers | 62 | Decades |
| 16 | All character sets | 105 | Billions of years |
| 24 | All character sets | 157 | Effectively unbreakable |
Password managers and storage
Never store passwords in plain text — use a dedicated password manager (Bitwarden, 1Password, KeePass) that encrypts your vault with a master password. Password managers also auto-fill credentials, making it practical to use unique, complex passwords for every site. Reusing passwords is the leading cause of account compromise: when one site is breached, attackers use credential stuffing to try the same password on hundreds of other services. A password manager eliminates this risk.
Special characters and compatibility
Some systems restrict which special characters are accepted in passwords — common allowed symbols include !, @, #, $, %, ^, &, *, (, ). Certain enterprise systems or legacy web apps reject symbols entirely. If a generated password is rejected, regenerate with symbols disabled and increase the length to compensate. For API keys and tokens, prefer alphanumeric-only passwords at 32+ characters for maximum compatibility across YAML config files, shell scripts, and .env files.
Worked examples
Strong 16-char password
Inputs: 16 chars · upper+lower+digits+symbols (94 pool)
Result: ≈105-bit entropy (log₂94¹⁶ ≈ 104.9)
Weak 8-char password
Inputs: 8 chars · lowercase only (26 pool)
Result: ≈37-bit entropy — crackable in hours
Glossary
- Entropy
- A measure of password unpredictability in bits — higher entropy means more possible combinations and stronger security.
- Brute force attack
- Systematically trying every possible password combination until the correct one is found.
- Credential stuffing
- Using leaked username/password pairs from one breach to attempt logins on other services.
- NIST SP 800-63B
- US government guidelines for digital identity that recommend minimum password lengths and ban periodic password rotation.
Related reading
Frequently Asked Questions
Why use Password Generator?
- Build strong passwords with adjustable length and full character set control
- Block look-alike characters like 0/O and l/1/I with a single toggle
- Inspect entropy bits to verify how resistant a password is before using it
- Generate multiple passwords at once to cover a batch of new account setups
Common use cases
- Create a unique password for a new account registration
- Regenerate a credential after a suspected phishing or data-breach incident
- Produce a high-entropy password for a new PostgreSQL database instance
- Set a 24-character master password for a newly configured password manager
- Generate an alphanumeric-only password for a system that rejects symbols
Get weekly tool tips & updates
New tools, power-user tips, and productivity hacks — delivered free every Friday.
No spam, ever. Unsubscribe with one click.
Related Generators
Passphrase Generator
Generate memorable, strong passphrases from random words with custom length, separators and capitalization. Crypto-random and private — nothing leaves your browser.
SSH Key Generator
Generate an RSA SSH key pair in your browser with an OpenSSH public key and a PEM private key. Free, private, and runs locally with the Web Crypto API.
Base64 Encoder & Decoder
Encode text or files to Base64, or decode Base64 strings back to text in seconds. Free, private, and fully in-browser now.
JSON Formatter & Validator
Format, validate, and minify JSON instantly. Includes syntax highlighting, error detection, and a collapsible tree view — free, private, in-browser.
Random Number Generator
Generate random numbers between any range instantly. Choose count, allow duplicates, and use dice shortcuts (d6, d20). Free online random number generator.
Random Picker
Pick a random item from a list online. Enter your options, spin, and get a winner instantly. Pick multiple winners without repeats. Free random choice picker.
Explore all Generators.