Perplexity

Perplexity is an AI-powered answer engine that responds to queries with direct, cited answers synthesized from live web sources, positioning itself as a challenger to traditional search. It combines its own orchestration with frontier and open models, and has expanded into an agentic browser (Comet) and a developer API, growing rapidly among users who prefer answers over lists of links.

Founded in 2022 by Aravind Srinivas and colleagues, Perplexity set out to reinvent search around large language models, returning synthesized answers with inline citations rather than ranked links. That format — conversational, sourced, and follow-up-friendly — found a fast-growing audience.

The product routes across multiple models (its own and third-party frontier and open models) and layers real-time retrieval on top, with a Pro tier and a growing set of features including the Comet agentic browser and Sonar API for developers. Its emphasis on citations targets trust and answer quality as differentiators.

Backed by prominent investors at a valuation in the tens of billions, Perplexity competes directly with Google's AI Overviews and AI Mode, OpenAI's ChatGPT search, and other answer engines. As a heavy consumer of model APIs, it also exemplifies the application-layer economics of building on top of frontier models.