Unleash the stories hidden in your photos.
CaptionAI transforms your static images into compelling narratives, witty one-liners, and viral-ready social posts instantly. Powered by next-generation AI, it sees what you see—and finds the perfect words to say it.
CaptionAI isn't just an image tagger; it's your creative writing partner. Whether you need a professional LinkedIn description or a hilarious caption for Instagram, CaptionAI adapts to your voice.
- 🧠 Advanced Visual Understanding: Goes beyond basic object detection to understand context, mood, and lighting.
- 🎨 Infinite Variations: Never settle for the first draft. Generate multiple unique angles for every image.
- 🎭 Tone Chameleon: Switch modes instantly—from Professional and Descriptive to Sarcastic, Funny, or Poetic.
- 🌡️ Creativity Control: Dial in the perfect balance between accurate description and wild imagination with our custom temperature slider.
- 🌍 Global Speak: Instantly generate captions in English, Spanish, Hindi, French, German, and more.
- 📱 Platform Optimized: Get output tailored specifically for Instagram, Twitter/X, LinkedIn, or TikTok layouts.
- #️⃣ Smart Hashtags: Boost your reach with AI-curated, trending hashtags relevant to your image content.
- 📜 Session History: Automatically saves your generated captions so you never lose a great idea.
Built with a modern, modular architecture designed for speed and scalability.
- Backend:
- Framework: FastAPI (High-performance, async Python web framework)
- AI Engine: Google Gemini 2.5 Flash (State-of-the-art multimodal model)
- Architecture: Modular service-based design with Pydantic validation
- Frontend:
- Core: React 19 + Vite (Blazing fast build & HMR)
- Styling: Tailwind CSS v3 (Custom design system)
- Animations: Framer Motion & Three.js (Immersive particle backgrounds)
- Icons: Lucide React
Follow these steps to run CaptionAI locally on your machine.
The brain of the operation.
cd backend
# Create a virtual environment (optional but recommended)
python -m venv venv
# Windows: venv\Scripts\activate
# Mac/Linux: source venv/bin/activate
# Install dependencies
pip install -r requirements.txt
pip install google-generativeai python-dotenv
# Create .env file with your API Key
echo "GEMINI_API_KEY=your_key_here" > .env
# Run the server
uvicorn main:app --reloadServer runs at: http://localhost:8000
The beautiful interface.
cd frontend
npm install
npm run devApp runs at: http://localhost:5173
CaptionAI/
├── backend/ # Python FastAPI Server
│ ├── app/
│ │ ├── api/ # REST API Routes
│ │ ├── core/ # Configuration & Secrets
│ │ ├── models/ # Data Validation Schemas
│ │ └── services/ # Business Logic (Gemini Code)
│ └── main.py # Application Entry Point
├── frontend/ # React Client
│ ├── src/
│ │ ├── components/ # Reusable UI Components
│ │ └── App.jsx # Main Application State
└── requirements.txt # Python Dependencies
Made with ❤️ using Gemini