Perplexity AI. Perplexity AI is a conversational search engine that uses large language models (LLMs) to answer queries using sources from the web and cites links within the text response. Its developer, Perplexity AI, Inc., is based in San Francisco, California.

History 

Perplexity was founded in 2022 by Aravind Srinivas, Andy Konwinski, Denis Yarats and Johnny Ho, engineers with backgrounds in back-end systems, artificial intelligence (AI) and machine learning:
 Srinivas, the CEO, worked at OpenAI as an AI researcher.
 Konwinski was among the founding team at Databricks.
 Yarats, the CTO, was an AI research scientist at Meta.
 Ho, the CSO, worked as an engineer at Quora, then as a quantitative trader on Wall Street.

Lawsuit 
On January 31, 2025, Perplexity was sued for alleged trademark infringement by Perplexity Solved Solutions (PSS), a software firm founded in 2017. The lawsuit, filed in the United States, claims that Perplexity AI's use of the name "Perplexity" violates PSS's federally registered trademark, potentially leading to consumer confusion. PSS had previously declined an offer from Perplexity AI to purchase the trademark in 2023. The legal action seeks to prevent Perplexity AI from using the name in its branding and marketing.

This lawsuit follows other legal challenges against Perplexity AI. In October 2024, The New York Times issued a cease-and-desist notice alleging unauthorized use of its content. Additionally, in January 2025, Dow Jones and the New York Post sued Perplexity AI, accusing the company of fabricating portions of news articles and falsely attributing them to the publishers.

Services 
Perplexity works on a freemium model. It also offers a paid enterprise version.

Free plan 
The free model uses the company's standalone LLM based on GPT-3.5 with browsing.

It uses the context of the user queries to provide a personalized search result. Perplexity summarizes the search results and produces text with inline citations.

Perplexity also enables users to use Pages to generate customizable web pages and research presentations based on user prompts.

Perplexity Pro 
 Provides access to an API
 Search both internal files and web content
 Asks the user clarifying questions to refine queries
 Enables users to upload and analyze local files, including images
 Has access to GPT-4, Claude 3.5, Grok-2, Llama 3 and in-house Perplexity LLMs 
 Able to generate images using AI via Playground v3, DALL-E, Stable Diffusion and FLUX 1

Shopping hub 
On November 18, 2024, Perplexity launched its shopping hub to attract users, backed by Amazon and leading AI chipmaker Nvidia. This will give users product cards showing relevant items in response to asked questions about shopping.

Internal Knowledge Search 
Internal Knowledge Search enables Pro and Enterprise Pro users to simultaneously search across web content and internal documents. Users can upload and search through Excel, Word, PDF, and other common file formats. Enterprise Pro users have a limit of 500 files for upload and indexing.

Finance 
In October 2024, Perplexity AI introduced new finance-related features, including looking up stock prices and company earnings data. The tool provides real-time stock quotes and price tracking, industry peer comparisons and basic financial analysis tools. The platform sources its financial data from Financial Modeling Prep (FMP) to ensure accuracy.

Spaces 
Perplexity Spaces was released in October 2024 as an AI-powered collaboration hub. The platform allows users to create customized knowledge spaces that combine web searches with personal file integration. Users can upload up to 50 different documents, with a 25MB size limit per file.

Assistant for Android 
In January 2025, Perplexity launched the Perplexity Assistant, an AI-powered tool designed to enhance the functionality of its search engine. The assistant is available on Android devices and is integrated into the Perplexity app. It can perform tasks across multiple apps, such as hailing a ride or searching for a song, and is capable of maintaining context across actions, allowing for more seamless task management. 

The Perplexity Assistant is powered by the company's search engine, granting it access to the web. This enables event reminders, including finding the right date and time and creating corresponding calendar entries. The assistant is also multi-modal, meaning it can use a phone’s camera to provide answers about the user’s surroundings or on-screen content.

Initially, the Perplexity Assistant is free in 15 languages, including English, Spanish, French, German, Japanese, Korean, and Hindi. Despite its promising features, Perplexity has acknowledged that the assistant is still in development and may not always function as expected. For instance, certain features, such as summarizing unread emails or upcoming calendar events, require users to enable a workaround based on notifications.

As a business 
As of April 2024, Perplexity has raised $165 million in funding, valuing the company at over $1 billion. 

As of December 2024, Perplexity closed a $500 million round of funding that elevated its valuation to $9 billion.

In July 2024, Perplexity announced the launch of a new publishers' program to share ad revenue with partners.

Perplexity AI plans to introduce ads on its search platform by Q4 of 2024.

On January 18, 2025, the day before the impending U.S. ban on Chinese social media app TikTok, Perplexity submitted a proposal for a merger with TikTok US.

Notable investors 
The following personalities and companies are among the most notable investors: 

 Jeff Bezos
 Nvidia
 Databricks
 Bessemer Venture Partners
 Susan Wojcicki
 Jeff Dean
 Yann LeCun
 Andrej Karpathy
 Nat Friedman
 Garry Tan

Concerns

Forbes 
In June 2024, Forbes publicly criticized Perplexity for using their content.

According to Forbes, Perplexity published a story largely copied from a proprietary Forbes article without mentioning or prominently citing Forbes. 

In response, Srinivas said that the feature had some "rough edges" and accepted feedback but maintained that Perplexity only "aggregates" rather than plagiarizes information.

Wired 
In June 2024, separate investigations by the magazine Wired and web developer Robb Knight found that Perplexity does not respect the robots.txt standard, which allows websites to stop web crawlers from scraping content, reportedly despite Perplexity claiming the opposite.

Perplexity also lists the IP address ranges and user agent strings of their web crawlers publicly, but according to Wired and Robb Knight, they use undisclosed IP addresses and spoofed user agent strings when ignoring robots.txt. 

Wired also stated that, in some cases, Perplexity may be summarizing: "not actual news articles but reconstructions of what they say based on URLs and traces of them left in search engines like extracts and metadata, offering summaries purporting to be based on direct access to the relevant text." In response, Srinivas stated in a phone interview that: "Perplexity is not ignoring the Robot Exclusions Protocol... We don't just rely on our own web crawlers, we rely on third-party web crawlers as well." Srinivas explained that the web crawler identified by Wired was owned by a third-party provider. 

When asked whether Perplexity would cease scraping Wired content using third parties, Srinivas responded that "it's complicated."

Amazon 
Amazon Web Services, which hosts the Perplexity crawler, has a terms of service clause prohibiting its users from ignoring the robots.txt standard. 

Amazon began a "routine" investigation into the company's usage of Amazon Elastic Compute Cloud.

Lawsuits 
In October 2024, The New York Times (NYT) sent a cease-and-desist notice to Perplexity to stop accessing and using NYT content, claiming that Perplexity is violating its copyright by scraping data from its website. 

NYT is also suing OpenAI and Microsoft for copyright infringement for similarly using millions of its articles to train the large language models that power ChatGPT. 

The cease-and-desist notice sent by NYT lawyers read in part:"Perplexity and its business partners have been unjustly enriched by using, without authorization, The Times's expressive, carefully written and researched, and edited journalism without a license." The same month, Dow Jones and New York Post filed a lawsuit against Perplexity, alleging copyright infringement. The lawsuit also alleges that Perplexity attributed quotes to an article on F-16 jets for Ukraine that never appeared in the original article.

On October 24, 2024, Perplexity released a blog post to address the lawsuits. It stated that the complaints are misleading and reiterated that it was open to revenue-sharing programs.

References

External links 

 

2022 software
Artificial intelligence companies
Chatbots
Metasearch engines
Software companies established in 2022
Virtual assistants