Perplexity AI
In plain wordsAn American company whose AI search engine answers questions in full sentences with links to its sources; news publishers have sued it for using their articles.
An American company whose 'answer engine' combines web search with language modelslarge language model, n.: A computer program trained on enormous amounts of text to predict the words that come next. At vast scale, that simple skill lets it chat, answer questions, translate, summarize and write code., returning written answers with citations instead of a list of links — an early mass-market application of retrieval-augmented generationretrieval-augmented generation, n.: Giving an AI an open-book exam: before answering, it looks up relevant passages in a set of documents and bases its reply on them, often citing where each point came from. to search. It uses models from several developers alongside its own, and in 2025 launched Comet, a web browser with a built-in agentAI agent, n.: An AI system that does not just answer but acts: given a goal, it decides on steps, uses tools such as a browser or code editor, checks the results and keeps going until the job is done. that can browse and act on the user's behalf. Its use of publishers' content has made it a defendant in copyright suits by Dow Jones and the New York Post (2024) and by Japanese newspapers (2025), and in August 2025 Cloudflare accused it of disguising its web crawlers to evade blocks, which it denied. It has offered publishers a revenue-sharing program since 2024.
Origin
Founded in August 2022 in San Francisco by Aravind Srinivas, a former OpenAI research scientist and its chief executive, with Denis Yarats, Johnny Ho and Andy Konwinski; its search product launched in December 2022.
Usage note
Not to be confused with perplexityperplexity, n.: A score for how surprised a language model is by real text; lower is better. A perplexity of 10 means guessing each next word is, on average, as hard for the model as guessing a ten-sided die's roll., the language-modeling metric whose name it shares.
Related
- retrieval-augmented generationretrieval-augmented generation, n.: Giving an AI an open-book exam: before answering, it looks up relevant passages in a set of documents and bases its reply on them, often citing where each point came from.
- AI agentAI agent, n.: An AI system that does not just answer but acts: given a goal, it decides on steps, uses tools such as a browser or code editor, checks the results and keeps going until the job is done.
- AI copyright litigationAI copyright litigation, n.: The many lawsuits in which authors, artists, news organizations, record labels and others accuse AI companies of copying their work without permission to build or run AI models.
- large language modellarge language model, n.: A computer program trained on enormous amounts of text to predict the words that come next. At vast scale, that simple skill lets it chat, answer questions, translate, summarize and write code.
- OpenAIOpenAI, prop. n.: The American company that makes ChatGPT and the GPT models. It began in 2015 as a nonprofit research lab and is now a for-profit company overseen by a nonprofit foundation.
- perplexityperplexity, n.: A score for how surprised a language model is by real text; lower is better. A perplexity of 10 means guessing each next word is, on average, as hard for the model as guessing a ten-sided die's roll.
Mentioned in
agentic browseragentic browser, n.: A web browser with an AI assistant built in that can do things for you online — reading pages, clicking, filling in forms, shopping or booking — instead of just showing you websites.