Duolingo AI Assistant – Chrome Extension Powered by ChatGPT & Gemini (Hackathon Project)

A Chrome extension built during a hackathon that integrates ChatGPT and Gemini APIs to provide real-time AI assistance inside Duolingo. It helps users understand grammar, translate sentences, and get instant explanations without leaving the page.

🚀 Overview

This project is a Chrome extension-based AI assistant built during a hackathon to enhance the Duolingo learning experience.

It integrates ChatGPT and Gemini APIs to provide real-time explanations, translations, and grammar support directly inside the Duolingo interface.

Instead of switching tabs or searching externally, users receive instant AI-powered assistance within the same learning flow.

🧠 Problem Statement

Language learners often face challenges such as:

• Difficulty understanding grammar rules in context
• Slow translation of sentences during exercises
• Lack of immediate explanations for answers
• Disruption caused by switching between apps or search engines

This creates friction and slows down the learning process.

💡 Solution

The extension solves this by acting as a real-time AI learning companion inside Duolingo:

• Detects exercise questions and user-selected text
• Sends contextual prompts to ChatGPT or Gemini APIs
• Generates instant explanations or translations
• Displays results in a lightweight overlay UI

This keeps the learning experience uninterrupted and interactive.

⚙️ Key Features

🤖 Multi-Model AI Support

• ChatGPT (OpenAI API)
• Gemini (Google AI API)
• Smart fallback between models for reliability

🧠 Context-Aware Understanding

• Extracts text from Duolingo exercises
• Understands selected sentences or words
• Builds structured prompts based on context

🪄 In-Browser AI Overlay

• Floating assistant panel inside Duolingo
• Non-intrusive UI design
• Instant answer rendering without page reload

⚡ Fast & Lightweight Architecture

• Async background processing
• Optimized API requests
• Minimal impact on page performance

🧰 Tech Stack

• Chrome Extension (Manifest V3)
• JavaScript / TypeScript
• OpenAI ChatGPT API
• Google Gemini API
• HTML, CSS (UI overlay)
• Chrome Content Scripts + Service Worker architecture

🏗 Architecture

The system is built using a modular Chrome extension design:

• Content Script → Extracts page content and user interaction
• Background Service Worker → Handles API communication
• AI Layer → Processes prompts via ChatGPT / Gemini
• UI Layer → Renders responses inside an overlay panel

🚧 Challenges & Solutions

🌐 Context Extraction from Duolingo UI

Duolingo dynamically changes DOM structure, making extraction tricky.

Solution: Implemented flexible DOM selectors and prioritized user-selected text for accuracy.

⚡ API Latency Management

AI responses can introduce delay during exercises.

Solution: Used asynchronous requests with loading states and lightweight caching.

🧩 Chrome Manifest V3 Limitations

Service worker lifecycle restrictions impacted continuous processing.

Solution: Split logic between content scripts and background worker for stability.

📌 Outcome

The final product is a real-time AI-powered learning assistant for Duolingo, improving language learning efficiency by providing instant explanations and translations directly inside the platform.

🏁 Hackathon Impact

This project demonstrates:

• AI integration (ChatGPT + Gemini APIs)
• Chrome extension development (Manifest V3)
• Real-time context-aware systems
• UX overlay engineering
• Product-focused rapid prototyping

💬 Final Note

This hackathon project showcases how AI can seamlessly enhance existing learning platforms by acting as an intelligent layer on top of them, without modifying the core application.