Perplexity is an AI-powered answer engine that combines real-time web search with large language models, delivering direct cited answers instead of link lists.
Founded in 2022 by ex-researchers from OpenAI, DeepMind, and Meta, Perplexity grew from 3,000 queries per day at launch to 780 million monthly queries by mid-2025, reaching 22 million monthly active users and a $18 to $20 billion valuation. The core distinction from other AI assistants is transparency: every response includes clickable citations linking to original sources, letting users verify claims rather than accepting AI output on faith.
Every answer is grounded in live web results through the Sonar model, built on Meta Llama 3.3 70B and optimized for web-grounded real-time responses. Pro subscribers can switch between GPT-4o, Claude, and other frontier models. Deep Research mode runs extensive multi-source investigations producing structured reports. The platform has expanded into specialized verticals including Perplexity Patents for conversational IP research. Firefox added Perplexity as a built-in search engine option in 2025, and it became the default AI assistant on Samsung Galaxy devices.
Free tier offers unlimited quick searches powered by the Sonar model. Pro is $20 per month with access to frontier models, unlimited file uploads, and Deep Research. Max tier offers higher limits for power users. API pricing starts at $5 per 1,000 requests.
Knowledge workers, students, consultants, analysts, and developers who need verifiable research fast. Ideal for fact-checking, competitive intelligence, and staying current. Less suited for creative writing or coding, where dedicated tools like ChatGPT or Claude perform better.