DuetReader

🌍 Read Anything, In 23+ Languages

Break free from pre-packaged lessons. Import articles from websites, paste text directly, or upload PDF documents and EPUB e-books. Whether reading Spanish news, Japanese novels, Korean webtoons, or French literature, DuetReader empowers you to learn from content that genuinely interests you.

🔄 Revolutionary Sentence-by-Sentence Translation

Experience precise sentence-by-sentence translations with synchronized highlighting. Watch each sentence illuminate in both source and translated text, making it effortless to understand exactly what each phrase means. Navigate using intuitive swipe gestures or our smart sentence slider while maintaining perfect context.

Multiple Translation Options:

• Offline Translation: On-device ML Kit models work without internet—perfect for travel or commuting
• Online Free Translation: Google Translate's powerful API at no cost
• Premium Cloud Translation: Connect your Google Cloud API key for enhanced accuracy

All translations are cached for offline access to your favorite content.

🔊 Listen and Learn with Dual Audio

DuetReader's text-to-speech system brings content to life with dual audio playback. Hear both source language and translation with independent speed controls. Perfect pronunciation through native-like speech, then reinforce understanding with translations. Autoplay mode creates an immersive, hands-free experience perfect for commuting or exercising.

Choose system-installed voices for offline learning or connect to Google Cloud Text-to-Speech for premium, natural-sounding narration.

🤖 AI-Powered Grammar Analysis

Unlock deeper understanding with AI sentence analysis powered by Google Gemini 2.5 Flash. Get detailed grammatical breakdowns explaining sentence structure, parts of speech, verb conjugations, and linguistic patterns. Like having a personal language tutor available 24/7.

🔒 Privacy-First, Offline-First Philosophy

Your data belongs to you. DuetReader delivers privacy and security:

• All reading history and translations stored locally on your device
• No analytics, tracking, or data collection
• No advertisements
• Cloud API keys encrypted and stored only on your device
• Works completely offline with on-device translation and TTS

Learn more about how we protect your privacy in our Privacy Policy.

🎨 Beautiful, Customizable Interface

Enjoy elegant light and dark themes adapting to system preferences, adjustable font sizes, smooth animations, intuitive gestures, and split-pane layouts on larger screens.

📚 Build Your Personal Language Library

Track your journey with comprehensive history management. Review articles, revisit passages, watch progress grow. Long-press to preview content, swipe to organize.

📱 Native Mobile Experience

DuetReader is built as a native mobile app for both Android and iOS devices. Enjoy smooth performance, seamless gestures, and a polished interface optimized for your smartphone or tablet. Take your language learning anywhere—on the bus, at the café, or relaxing at home.

🗣️ Supported Languages (23+)