DeepSeek AI is a free and open-source browser extension tool designed to provide comprehensive analysis and intelligent responses to web content. Users can highlight any text on a webpage and utilize DeepSeek's advanced AI models to gain insights and answers. The extension offers features such as real-time AI streaming responses, customizable keyboard shortcuts, Markdown rendering, LaTeX math formulas, and the ability to regenerate responses if needed. DeepSeek AI aims to enhance user experience in tasks like academic research, data analysis, and understanding complex information during casual browsing.