# Password Generator — Free Secure Online Tool
https://password-generator.usetool.org/

> Password Generator is a free, privacy-first online tool that generates cryptographically secure random passwords entirely in your browser. It uses the Web Crypto API (crypto.getRandomValues) with rejection sampling to eliminate modulo bias. No passwords are ever sent to a server, stored in any database, or logged anywhere. Zero network requests with password data.

## Features
- Cryptographically secure generation via Web Crypto API (CSPRNG)
- Customizable password length (8-128 characters)
- Character set toggles: uppercase (A-Z), lowercase (a-z), digits (0-9), symbols (30 chars)
- Exclude ambiguous characters option (I, l, 1, O, 0)
- Batch generation of up to 50 passwords at once
- Password strength indicator with entropy calculation (bits)
- Estimated brute-force crack time (at 10 billion attempts/second)
- One-click copy to clipboard (single or batch)
- Syntax coloring: digits in blue, symbols in amber
- Dark mode support
- Mobile responsive design (320px+)
- Rejection sampling eliminates modulo bias for uniform character distribution
- Guaranteed coverage: at least one character from each enabled character set

## Use Cases
Everyday users creating online accounts, developers generating API keys and secrets, sysadmins provisioning server and WiFi passwords, security-conscious teams needing bulk credentials, parents setting up accounts for children, anyone who needs a strong password without installing software.

## Security Model
- 100% client-side: passwords never leave the browser
- Uses crypto.getRandomValues(), not Math.random()
- No server-side processing, no API calls, no database
- No localStorage, sessionStorage, or cookie storage of passwords
- No console.log of passwords even in development
- HTTPS required (Web Crypto API requires secure context)

## Limitations
- Character-based passwords only (no passphrase/diceware generation)
- No password strength checking for user-provided passwords
- No password storage or password manager functionality
- No server-side generation option
- No API access (browser-only tool)
- Symbols exclude double-quote and backslash by design (HTML/shell compatibility)

## Technical
Built with Astro 5 (static site generator), Preact + Signals (~4KB interactive island), Tailwind CSS. Zero external dependencies for password generation logic. Part of the UseTool suite at usetool.org.