Offline Random Password Generator

A fully offline, single-file, browser-based random password generator featuring custom password length, character type selection, excluded characters, custom special symbols, weak-password keyword blocking, batch generation, one-click copy, and bilingual UI — all powered by the browser's crypto.getRandomValues for cryptographically secure randomness. Every password is generated locally; no data ever leaves the browser.

Preview

Features

🔐 Password Generation Core

• Custom password length (1–20 characters)
• Generate 1–20 passwords at once
• Uses crypto.getRandomValues for cryptographically secure randomness with rejection sampling to avoid modulo bias

🎛️ Password Rules

• Character type selection: uppercase letters, lowercase letters, digits, and special symbols
• Force first letter uppercase: the first character excludes the ambiguous letter I to avoid confusion with digit 1 and lowercase i
• Custom excluded characters: specify any characters you don't want — defaults to ~^()
• Custom special symbols: specify exactly which symbols to use — defaults to !@#$%&*
• Weak-password keyword blocking: over 30 common weak-password words are blocked by default, including admin, pass, root, 123456, etc.

🧠 Smart Rules

• Each selected character type accounts for at least 25% of the final password, ensuring complexity
• No consecutive special symbols to improve security
• Characters are shuffled after generation for an even random distribution

🖱️ Copy & Interaction

• Per-password copy button with grey confirmation feedback
• Copy-all button for batch copy, passwords separated by newlines
• Two-column layout with independently scrollable password list

🌐 Bilingual UI

• Automatically displays Chinese or English based on browser language
• Chinese browsers default to Chinese; non-Chinese browser languages default to English
• Manual language switching is persisted via localStorage

💾 Settings Persistence

• All settings are auto-saved after each password generation
• Settings are restored automatically when you reopen the page
• Built-in 5MB localStorage quota protection

🔖 Tab Icon

• Inline lock-shaped SVG favicon that matches the page's gradient theme
• Makes the browser tab easy to identify

Usage

Open password-generator.html directly in a browser. No deployment or server is required; everything runs offline.

Changelog

See VERSIONS.md for detailed version history.

Highlights

• ✨ Single file, no dependencies, fully offline
• 🎨 Clean, modern gradient UI
• 🔒 Privacy-first: passwords are generated locally and never uploaded
• 🛡️ Smart rules ensure password complexity
• 💾 Settings auto-saved, ready to use on next visit
• 🌐 Bilingual Chinese/English with automatic browser language detection