If you post car content on Instagram, you know the pain of writing fresh captions every time. I built an AI-powered caption generator that helps you auto-generate captions, hashtags, and even TikTok sound ideas — just from a car photo.

In this article, I’ll show you how I built it using:

  • 🧠 OpenAI GPT-4 Vision
  • 🖼️ Image analysis
  • 🌐 Streamlit app interface
  • 🛠️ My personal caption history as training context

🔧 What We'll Build

Image description

🚀 Tech Stack

📁 Project Structure 

car-caption-generator-ai/
├── app.py                     # Streamlit app logic
├── utils/
│   ├── vision.py              # GPT-4 Vision logic
│   ├── captions.py            # Captions and hashtags generator
│   └── prompts.py             # Stores the prompt template
├── requirements.txt           # Dependencies
└── README.md

Setup Instructions

1 .Clone the repo: 

git clone https://github.com/Navashub/caption_generator_ai.git
cd car-caption-generator-ai

2.Create and activate a virtual environment: 

python -m venv myvenv
source myvenv/bin/activate  # Windows: myvenv\Scripts\activate

3.Install dependencies: 

pip install -r requirements.txt

4.Add your OpenAI API key in a .env file 

OPENAI_API_KEY=""

5.Run the app: 

streamlit run app.py

🧠 How It Works

1.The app uses GPT-4 Vision to describe your uploaded car image.
2.That description is passed into a prompt template (along with your past captions).
3.The model returns:
- An Instagram caption
- Hashtags
- TikTok sound vibes

Here’s a sample output for an Audi RS5:

"Brutal beauty in carbon black. The RS5 doesn’t speak — it growls. Welcome to the autobahn attitude. 💨🔥
#RS5Power #FavouriteFourRings #AudiLife"