About this extension

Language Lens

Transform your daily browsing into a language learning experience! Language Lens replaces words on webpages with their foreign equivalents, helping you learn naturally as you read.

How It Works

1. **Setup an AI Language Model** - Choose your language model and API key - this is needed to translate sentences properly
2. **Choose Your Language** - Select which language you want to learn
3. **Browse Normally** - Visit any website you usually read
4. **Learn Naturally** - Some words will be replaced with their foreign equivalents
5. **Hover to Learn** - Mouse over any translated word to see its meaning
6. **Automatic new words addition** - New words are added to your vocabulary based on your knowledge

Features

• **Smart Word Selection** - Gradually introduces new words based on your knowledge
• **Instant Translations** - Hover over any translated text to see its original meaning
• **Progress Tracking** - Automatically tracks which words you know well
• **Fast & Light** - Minimal impact on your browsing experience

Setup Instructions

1. **Install the Extension**
- Click "Add to Firefox" and grant the necessary permissions
- The Language Lens icon will appear in your browser toolbar

2. **Configure Language Model**
- Click the Language Lens icon to open settings
- Under "LLM Settings", choose your preferred provider:
- OpenAI (GPT models)
- Anthropic (Claude)
- Google (Gemini)
- OpenWebUI (for local models)
- Enter your API key for the chosen provider
- Select your preferred model

3. **Choose Learning Language**
- Select your target language from the dropdown
- Available languages include Japanese, Chinese, Korean, Spanish, French, German, Polish, Welsh, and Latin

4. **Optional: Configure Domain Filtering**
- Use "Domain Filtering" to control where the extension works
- Choose between blacklist (block specific sites) or whitelist (only work on specific sites)
- Add domain patterns like "example.com" or "*.example.org"

Using the Extension

1. **Managing Your Vocabulary**
- Add new words manually using the "Add New Word" form
- Use "Suggest Related Words" to get AI-powered word suggestions
- Search your vocabulary using the search bar
- Remove words by clicking the × button
- For Japanese: toggle kanji display for individual words

2. **Reading Webpages**
- Browse websites normally
- Some English words will be replaced with their foreign equivalents
- Hover over translated words to see:
- Original sentence
- A list of translated words
- Click the 🔊 icon to hear the pronunciation

3. **Track Your Usage**
- View token usage under "Token Usage"
- Set daily and monthly token limits

Privacy & Data Usage

• Your API key is stored locally and used only for translations
• Word lists and settings are stored in your browser
• No personal data is collected or shared
• Token usage is tracked locally for your reference
• Sentences to be translated are sent to your selected AI provider - this is the only data that leaves your browser

Developer comments

For each supported language, a mapping of <source language>: <target language> is maintained in local storage. Whenever an allowed page (by default all pages) is loaded, all visible text on the page is chunked into sentences. Any sentence that contains a known word gets send to a background process that batches sentences to be translated, and sends them along with the list of known words, to an LLM to be translated. The original sentence is then replaced with the resulting translation.

There is some caching done to limit token usage, but generally speaking, each sentence to be translated gets sent to an LLM. Sentences that don't contain known words are ignored.

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Release notes for 1.0.10

allow import/export of all words

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