Password Generator
Create cryptographically secure passwords with custom length, character sets, and strength indicators. Your passwords never leave your browser.
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.
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
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Why use Password Generator?
- Cryptographically random generators for secure use cases
- Fully configurable output — length, charset, quantity
- Download or copy output in one click
- No data logged or stored — 100% private generation
Common use cases
- Generate a strong random password for a new account
- Create test data with realistic-looking names and emails
- Produce random numbers for a classroom lottery
- Generate Lorem Ipsum placeholder text for mockups
- Create unique UUIDs for software development
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