Underline

AI-powered language learning assistant with contextual lookups.

Underline is your intelligent language learning companion powered by advanced AI. Whether you're reading articles, studying documents, or browsing the web, Underline helps you understand and learn new vocabulary effortlessly. Key features: AI-powered word lookup Get Chinese definitions, English explanations, phonetic transcriptions, and contextual analysis for selected words. Contextual example sentences See bilingual example sentences that show how a word is used in real reading contexts. Smart vocabulary management Save useful words to your personal vocabulary list and review them later from the extension popup. Flexible configuration Use your own OpenAI-compatible API key, choose a model, and optionally configure a custom Base URL. How it works: 1. Install the extension and enter your API key in Settings. 2. Select any word or phrase on a webpage. 3. Open the Underline lookup panel. 4. Review the AI-powered definition and examples. 5. Save useful words to your vocabulary list. Underline is designed for English learners, students, professionals, and anyone who wants to build vocabulary while reading on the web. Privacy note: Your vocabulary, settings, and API key are stored locally in Chrome extension storage. Selected text is sent only to the AI API endpoint you configure when you request a lookup.