Deep IELTS

AI-powered IELTS writing checker.

Deep IELTS is a free AI-powered IELTS writing checker, trained on over hundreds of real essays. It gives accurate score predictions and practical feedback, just like a real examiner.

Features

• Task 1 Academic & General Scoring - Get band score breakdowns with AI-generated feedback and sample answers
• Task 2 Scoring - Instant essay analysis with detailed feedback on argument, structure, vocabulary, and grammar
• Progress Tracking - Monitor your improvement over time with performance analytics
• Instant AI Feedback - Receive examiner-like feedback within seconds
• PDF Export - Download feedback as formatted PDFs for offline study
• Image Upload - Upload charts and diagrams for Task 1 with automatic data extraction
• Flexible Submissions - Upload files, paste text, or write directly in the editor
• User Accounts - Save submissions, track progress, and access premium features

Tech Stack

Frontend

• Next.js 15.3.5 - React framework with App Router
• React 19 - UI library
• TypeScript - Type-safe development
• Tailwind CSS 4 + Shadcn UI - Utility-first CSS framework
• React Hook Form - Form management
• Zod - Schema validation
• TanStack Query - Data fetching and caching
• Zustand - State management
• Recharts - Data visualization

Backend & Services

• Firebase - Authentication, Firestore database, and Cloud Storage
• OpenAI API - AI-powered essay analysis and feedback generation
• Redis (ioredis) - Rate limiting and caching
• Resend - Email service for verification codes
• Paddle - Payment processing and subscription management

Infrastructure & Tools

• Vercel - Hosting and deployment
• Sentry - Error monitoring and performance tracking
• Pino - Structured logging
• Sharp - Image processing
• md-to-pdf - PDF generation from Markdown

Development Tools

• ESLint - Code linting
• Prettier - Code formatting
• Turbopack - Fast bundler for development

Installation

Prerequisites

• Node.js 20+ and pnpm
• Firebase project with Authentication, Firestore, and Storage enabled
• Redis instance (local or cloud)
• OpenAI API key
• Paddle account (for payment processing)
• Resend API key (for email verification)
• Sentry account (optional, for error monitoring)

Setup Steps

1. Clone the repository

   git clone <repository-url>
   cd deepielts

2. Install dependencies

   pnpm install

3. Set up environment variables

   Copy the example environment file:

   cp env-example .env.local

   Fill in all required environment variables in .env.local:

   • App Configuration: NEXT_PUBLIC_BASE_URL, NEXT_PUBLIC_API_BASE_URL
   • Firebase: All NEXT_PUBLIC_FIREBASE_* and FIREBASE_ADMIN_* variables
   • JWT: JWT_ACCESS_SECRET, JWT_REFRESH_SECRET
   • Resend: RESEND_API_KEY
   • OpenAI: OPENAI_API_KEY
   • Redis: REDIS_URL
   • Paddle: All NEXT_PUBLIC_PADDLE_* and PADDLE_* variables
   • Sentry: All SENTRY_* variables (optional)

4. Run the development server

   pnpm dev

   The app will be available at http://localhost:3003

5. Build for production

   pnpm build
   pnpm start

Additional Setup

• Firebase: Configure Firebase Authentication (Email/Password or Google), set up Firestore security rules, and configure Cloud Storage buckets.
• Redis: Ensure Redis is running and accessible at the REDIS_URL you configured.
• Paddle: Set up products and pricing in your Paddle dashboard and configure webhooks.

TODO:

• [] Fix export to docx
• [] Improve payment, make it robust
• [] Improve Sidebar UI