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Password Generator

The Password Generator creates unpredictable strong passwords instantly using cryptographically secure random numbers. Supports 4-128 character length, uppercase/lowercase/numbers/symbols combinations, and bulk generation. All processing happens in-browser with no external transmission.

What You Can Do

The Password Generator instantly creates strong, unpredictable random passwords. Freely customize length and character types (uppercase, lowercase, numbers, symbols) to create unique secure passwords for each service. All processing happens in your browser, so your passwords are never transmitted externally.

✅ Length Control: Freely set from 4 to 128 characters
✅ Character Selection: Customize combinations of uppercase, lowercase, numbers, and symbols
✅ Bulk Generation: Generate multiple passwords at once with one-click copy

Generate multiple passwords at once and copy with one click. Recommended for use with password managers.

🔐 Generation Settings

Password Length

characters

Character Types

Uppercase (A-Z) Lowercase (a-z) Numbers (0-9) Symbols (!@#$%^&*)

Generation Count

Allow duplicate characters

📋 Generated Passwords

Generated passwords will appear here

💼 Use Cases

Creating new accounts - Generate strong passwords that are hard to guess
Regular password changes - Create complex passwords that meet security policies
Using different passwords per service - Prevent password reuse with random generation
When symbols are required - Select character types to meet requirements
Prioritizing security over memorability - Use with password managers

How to Use

📌 Basic Usage

Simply select password length and character types, then click "Generate Password" to create secure random passwords.

💡 Recommended Settings

Length: Minimum 12 characters recommended (16+ characters is more secure)
Character types: Include all - uppercase, lowercase, numbers, and symbols
Duplicates: Allowing duplicates creates passwords that are harder to guess

⚙️ Options

Generation count: Generate multiple password candidates at once
Duplicate characters: Control whether the same character can be used multiple times

🔒 Security Tips

Use different passwords for each service
Change passwords regularly
Save generated passwords in a password manager (recommended)
Avoid easily guessed information like birthdays or names

🔬 How Password Strength Works

Entropy (Strength Indicator)

Password strength is measured by "entropy (information content)", expressed in bits. For example, a 16-character password containing uppercase, lowercase, numbers, and symbols has approximately 104 bits of entropy, which would take even modern supercomputers thousands of years to crack.

Formula: Entropy = log₂(character types^password length)
Example: 16 characters, 94 character types → log₂(94¹⁶) ≈ 104 bits

Attack Methods and Countermeasures

Dictionary attack: Tries common words and known password lists. Completely prevented by random generation
Brute force: Tries all combinations. 12+ characters makes this virtually impossible (would take tens of thousands of years at 10 billion attempts per second)
Rainbow table: Uses pre-computed hashes. Prevented by using different passwords for each service

NIST Recommended Standards (2024)

The National Institute of Standards and Technology (NIST) recommends a minimum password length of 8+ characters, with 12-16 characters being ideal. This tool's default setting (16 characters) meets NIST standards. NIST also states that "regular password changes are unnecessary," recommending changes only when a data breach occurs.

❓ Frequently Asked Questions

A. Yes. We use JavaScript's cryptographically secure random number generator (Crypto.getRandomValues), which generates unpredictable passwords. All processing happens in your browser and passwords are never sent to servers.

A. We strongly recommend using a password manager (1Password, LastPass, Bitwarden, etc.). While browser auto-save is convenient, dedicated tools offer better security and sync across multiple devices.

A. According to NIST's latest guidelines (2024), regular changes are unnecessary. However, change immediately if a service experiences a data breach.

A. If long enough (20+ characters), passwords without symbols can be secure. However, many services require symbols, so we recommend the default settings (all character types).

📅 Last Updated: 2025-12-27 | 💬 Feedback: Send Feedback