What is a Password Generator?
A password generator is a tool that creates unpredictable random passwords using cryptographically secure random numbers. When creating passwords manually, unconscious patterns tend to emerge, but this tool generates hack-resistant passwords through completely random combinations. Beyond random characters, you can also create easy-to-remember passphrases like 'spring-cat-rainbow-ocean'.
It uses the browser's Web Crypto API to generate passwords securely on your local device without going through any server. After generating, you can instantly verify if the password has been exposed in known data breaches using the HIBP (Have I Been Pwned) database — your password is never transmitted thanks to the k-anonymity protocol.
Key Features
Cryptographically Secure
Uses Web Crypto API (crypto.getRandomValues) to generate truly unpredictable random passwords.
Strength Indicator
Calculates password entropy and displays strength in real-time as Weak, Fair, Strong, or Very Strong.
Flexible Character Options
Freely choose from uppercase (A-Z), lowercase (a-z), numbers (0-9), and symbols (!@#$%...) in any combination.
Bulk Generation & History
Generate up to 10 passwords at once and review your generation history within the current session.
Breach Check (HIBP)
Instantly verify if your generated password has appeared in known data breaches via Have I Been Pwned. The k-anonymity protocol ensures your password is never transmitted.
Korean & English Passphrases
Generate easy-to-remember passphrases like 'spring-cat-rainbow-ocean' in Korean or English. Customize word count and separator freely.
How to Use
- Set Length — Use the slider to set password length between 8 and 128 characters. 16 or more is recommended.
- Select Options — Toggle character types (uppercase, lowercase, numbers, symbols). For a passphrase, switch the mode to 'Passphrase'.
- Click Generate — Press the 'Generate Password' button to instantly create a password matching your settings.
- Copy and Use — Click the copy button next to the password to copy it to your clipboard. Paste it into the service you need.
- Check for Breaches (Optional) — Click 'Check Breach' to search the HIBP database and confirm your password hasn't been exposed in known data leaks.
Use Cases
Website Registration
Create unique, strong passwords when signing up for new websites or apps to keep your accounts secure.
Wi-Fi Password Setup
Set a strong random password for your home or office Wi-Fi to prevent unauthorized access.
Development & Testing
Quickly generate random strings for API keys, secret tokens, test passwords, and other development needs.
Regular Password Changes
Easily generate new strong passwords when regularly updating passwords according to security policies.
FAQ
Is this password generator secure?
Yes, this password generator uses the browser's Web Crypto API (crypto.getRandomValues) to generate cryptographically secure random numbers. All processing occurs in your browser and nothing is sent to any server.
What makes a password secure?
A secure password is at least 12 characters long and includes uppercase letters, lowercase letters, numbers, and special characters. Avoid dictionary words and personal information (birthdays, names), and use a unique password for each service.
What is the ideal password length?
A minimum of 12 characters is recommended, and 16 or more is even better. Longer passwords exponentially increase resistance to brute force attacks. Use 20+ characters for critical accounts.
Where are the generated passwords stored?
Generated passwords are only displayed in the current browser session history and disappear when you close the page. Nothing is stored on servers or transmitted externally. We recommend using a password manager for secure password storage.
Can I generate multiple passwords at once?
Yes, you can generate up to 10 passwords at once. Set the desired count and click the generate button to create multiple passwords with the same options (length, character types) simultaneously.
How do I check if my password has been exposed in a data breach?
After generating a password, click the 'Check Breach' button to cross-reference it against the HIBP (Have I Been Pwned) database, which contains billions of exposed accounts. Using the k-anonymity technique, only the first 5 characters of the SHA-1 hash are sent — your actual password is never transmitted, making the check completely safe.
What is a passphrase and is it more secure than a regular password?
A passphrase is a password made of multiple words, like 'summer-cat-ocean-happy'. It's easy to remember while being long enough to resist brute-force attacks. Setting 6 or more words produces stronger security than a typical 12-character random password. Both Korean and English passphrases are supported.
Can I generate a safe numeric PIN for banking or credit cards?
Yes, select the 'PIN' preset to quickly generate a number-only password. However, a 4-digit PIN has only 10,000 possible combinations and is very weak. For bank app passwords that support letters and numbers, we recommend the 'Banking' preset (12 characters, uppercase + lowercase + numbers). Always use different passwords for each service and store them in a password manager.
Privacy Notice
This password generator performs all processing in your browser. Generated passwords are never sent to any server, and the history is completely cleared when you close the page. No data is stored externally, so you can use it with complete confidence.