vs a search engine
Google gives you a list of links to read yourself. Perplexity reads them for you and writes the answer, while still showing the links.
The basics
What is Perplexity AI?
Perplexity AI is an answer engine: a mix of a search engine and an AI assistant. Instead of a page of links, you get a written answer built from current web pages, with sources you can open and check.
It's made by Perplexity AI, Inc., a San Francisco company founded in 2022 by Aravind Srinivas, Denis Yarats, Johnny Ho and Andy Konwinski. The first version launched in December 2022. Today it runs on the web, on iPhone and Android, on desktop, and inside Perplexity's own Comet browser.
You can use it free without an account. Signing up saves your history, and paid plans raise usage limits and unlock extra tools like Deep Research and Perplexity Computer.
- Type
- AI answer engine
- Founded
- 2022
- Headquarters
- San Francisco
- Free plan
- Yes
Under the hood
How Perplexity AI works, step by step
Every answer goes through the same five stages, usually in a few seconds.
- You ask a questionType or speak naturally. Perplexity works out what you mean, including follow-ups that refer to earlier questions in the thread.
- It searches the webIt turns your question into one or more search queries and runs them on the live web. Pro Search runs several searches for harder questions.
- It reads and ranks sourcesIt opens the most relevant pages, pulls out the passages that answer your question, and favors trustworthy, recent sources.
- An AI model writes the answerA large language model combines those passages into a short, readable answer, in the format you asked for: bullets, a table or steps.
- Every claim gets a citationNumbers like [1] and [2] link each statement to the page it came from, so you can verify it yourself.
This approach is called retrieval-augmented generation (RAG): the model writes from documents it just retrieved, not only from what it learned in training. That's why answers can be current and checkable.
Compared
How it differs from Google and ChatGPT
vs a chatbot
A chatbot can answer from what it learned in training, which may be out of date. Perplexity searches first, so answers reflect the web today.
Sources come first
Citations are part of every answer, not an add-on. That makes it well suited to research, fact-checking and anything you need to back up.
| Perplexity AI | Search engine | AI chatbot | |
|---|---|---|---|
| Gives a written answer | Yes | Sometimes (summaries) | Yes |
| Uses the live web | Yes, by default | Yes | Only when it searches |
| Cites every claim | Yes | Links only | Varies |
| Follow-up questions | Yes | Limited | Yes |
Technology
The AI models behind Perplexity
Perplexity's default model is Sonar, its own model tuned for fast, grounded answers. On paid plans you can switch the writing step to other leading models, including ones from OpenAI, Anthropic and Google.
For bigger jobs, Deep Research runs dozens of searches and writes a long report, and Perplexity Computer is an agent that carries out multi-step tasks. Developers can use the same search-grounded answers through the Sonar API.
Limits to keep in mind
- It can misread a source or quote a weak one. Open the citations for anything important.
- It's only as current as what's online; paywalled and private content is usually out of reach.
- For health, legal or money decisions, treat answers as a starting point and confirm with a professional.
FAQ
Questions about how Perplexity works
Is Perplexity AI free?
Yes. The free plan gives you cited AI search on the web and in the apps. Paid plans (Pro, Max) add higher limits, more Deep Research, a choice of AI models and agent tools.
Does Perplexity search the live web?
Yes. For most questions it runs a fresh web search at the moment you ask, so answers can include news and data published minutes earlier.
Which AI models does Perplexity use?
Perplexity uses its own Sonar models by default. Paid plans let you pick models from OpenAI, Anthropic, Google and others for the writing step.
Are Perplexity's answers always accurate?
No. It can misread a source or rely on a weak one. The citations exist so you can check, so open them for anything important.
Is Perplexity a search engine or a chatbot?
Both, in a way. It works like a search engine (live web results) but replies like a chatbot (a written answer you can follow up on). Perplexity calls it an answer engine.
Keep reading
Try it
See how it works for yourself
Ask your first question free on Perplexity's official site. No payment needed to start.