Du↔Sie Formalizer

About

**Du↔Sie Formalizer** instantly converts German text between informal "Du" and formal "Sie" address using Claude AI (Anthropic). Whether you are writing a business email, a casual message, or academic correspondence, get the register right every time.

### How it works

1. Click the extension icon (or right-click any selected text on any page)
2. Choose Du→Sie or Sie→Du
3. The conversion streams in real time — no waiting for the full result

### Three conversion modes

- **Standard** — Accurate pronoun and verb conversion while preserving original tone
- **Polished** — In addition to Du/Sie conversion, improves sentence flow and removes colloquialisms
- **Strict Corporate** — Maximum formality: eliminates contractions, applies the highest level of business register, and suggests formal salutations where needed

### Where you can use it

- **Popup** — Quick 320px window for instant conversions
- **Side Panel** — Full workspace with side-by-side diff view highlighting every changed word, plus conversion history (last 10 entries)
- **Context Menu** — Right-click any selection on any page to convert without leaving the page; the floating card lets you replace, copy, or retry

### Features

- Streaming output — see results as they arrive
- Side-by-side LCS diff — every changed word is highlighted (red strikethrough for removed, green underline for added)
- Conversion history — restore any of the last 10 conversions with one click
- Tone intensity slider — Standard, Polished, or Strict Corporate
- Dark mode — automatically adapts to your system theme
- RTL support — interface works in Arabic, Hebrew, Farsi, and Urdu locales
- Keyboard shortcut — Ctrl+Enter (Cmd+Enter on Mac) to convert
- Fully localised in English and German

### Privacy

- Your API key is stored locally in your browser and sent **only** to the Anthropic API
- The text you convert is sent to Anthropic's API — nothing is stored or logged by the extension
- No analytics, no tracking, no cookies, no third-party servers
- Open source and fully transparent

### Requirements

- A valid Anthropic API key (available at console.anthropic.com)
- Chrome or any Chromium-based browser