PasswordGenerator

An advanced, privacy-friendly, in-browser password generator (single HTML file). Generates passwords locally with strength feedback, multi-password output, and optional local history/export.

Quick start

1. Open PasswordGenerator.html in any modern browser (no server or install required).
2. Choose Length, Quantity, and Character types.
3. (Optional) Expand Advanced to refine generation rules.
4. Click Generate (or press Ctrl/⌘ + Enter).
5. Use the output actions to Reveal, Copy, Regenerate, Save, or Export.

Features

Modern UI & layout

• Modern 2-column responsive layout:
  • Left: settings and generation controls
  • Right: output, strength/entropy, multi-password list, and saved history
  • Automatically stacks for smaller screens
• Theme switcher with persistent preference:
  • System, Light, Dark, High-contrast
  • Reacts to OS theme changes when in System mode
• Keyboard shortcut hint visible in the header for quick discovery
• Toast notifications for feedback (copy success/failure, warnings, actions)
  • Dismiss via close button or Esc

Password length & quantity

• Length slider + numeric input with live label
  • Range: 4–64
• Quantity control to generate multiple passwords per run
  • Range: 1–10
  • Additional generated passwords are shown in a list with per-item actions

Character set controls

• Built-in character types:
  • Uppercase (A–Z)
  • Lowercase (a–z)
  • Numbers (0–9)
  • Symbols (enabled by user; off by default for compatibility)
• Custom characters input:
  • Adds your own characters to the generation set
  • Automatically de-duplicates repeated characters

Advanced options (accordion)

• Exclude similar characters (helps readability / reduces confusion):
  • Filters: i, l, 1, L, o, 0, O
  • Applies across all enabled groups (including custom characters)
• Exclude ambiguous symbols:
  • Filters common “hard-to-type / easy-to-mistake” punctuation (e.g., braces/brackets and similar)
  • Applies to the symbol group
• Require each selected type:
  • Ensures the generated password contains at least one character from every enabled set
  • If Custom characters are provided and this option is enabled, at least one custom character is included
• Convenience toggles:
  • Auto-copy on generate (copies the primary output password)
  • Auto-save to history (saves the primary output password automatically)

Output tools

• Read-only password output field with icon actions:
  • Show/Hide (reveal toggle)
  • Copy
  • Regenerate
• Strength meter (0–100) with label:
  • Weak / Medium / Strong / Very strong
• Entropy estimate (bits) and charset size indicator:
  • Displays an estimated entropy value based on length and effective character set size
  • Shows the total unique characters available in the final charset

Inline validation & safe disabling

• Inline validation messaging explains invalid configurations and prevents actions:
  • Disables Generate/Regenerate/Copy when invalid
  • Example: requiring each type when length is too short for the number of selected groups

Multi-password output list

• When Quantity > 1:
  • Additional generated passwords appear in a list
  • Each item includes:
    • Copy
    • Save (stores that specific password into history)

History & export

• Save to history button for the main output password (manual save)
• Saved history includes:
  • Local timestamps for each entry
  • Per-entry actions:
    • Use (loads into the main output field)
    • Copy
    • Delete
• History capacity limit:
  • Keeps up to 40 saved entries (oldest entries are dropped automatically)
• Clear history with a non-blocking confirm step:
  • Requires a second click within a short window (“Confirm clear”) to avoid accidental loss
• Export to .txt:
  • Exports:
    • Current output password (if present)
    • Additional generated passwords (if present)
    • Saved history (timestamped)
  • File name: passwords-export.txt

Persistence (local storage)

• Settings automatically persist in the browser via localStorage:
  • Length, quantity, selected character types, advanced toggles, and custom characters
• Theme mode persists in the browser
• History persists in the browser until deleted/cleared

Keyboard shortcuts

• Ctrl/⌘ + Enter — Generate
• Ctrl/⌘ + C — Copy (only when the password field is focused)
• Esc — Dismiss toast notification

Security & privacy notes

• Passwords are generated locally in your browser.
• Randomness:
  • Uses crypto.getRandomValues when available (preferred for security)
  • If unavailable, falls back to Math.random and shows a warning toast (reduced security)
• Clipboard:
  • Copy uses the Clipboard API when available, with a fallback method for older contexts
  • Some browsers or environments may block clipboard access; the UI will notify you
• Local storage:
  • If you enable saving (or use auto-save), passwords are stored in browser localStorage.
  • Avoid saving passwords on shared/public machines; clear history when finished.

Defaults & limits

• Default length: 16
• Default quantity: 1
• Default enabled types: Uppercase, Lowercase, Numbers
• Symbols: off by default
• Length bounds: 4–64
• Quantity bounds: 1–10
• Saved history cap: 40 entries