Perplexity AI is an advanced AI chatbot platform that provides instant, real-time answers by synthesizing web content and leveraging multiple large language models. It offers both quick responses for straightforward queries and a Deep Research mode for in-depth, expert-level analysis, iteratively searching and reasoning through hundreds of sources to generate comprehensive reports. Users can select from top-tier models like GPT-4.1, Claude 4.0 Sonnet, Sonar Large, and Gemini 2.5 Pro, or let the system automatically choose the best model for their needs. Perplexity AI is designed for a wide range of tasks, from finance and marketing research to coding and document analysis, and supports exporting and sharing of research outputs. The platform is accessible via web and mobile apps, with both free and subscription-based tiers available.