Baidu

• 1. Introduction

  ›

  Baidu, whose name comes from the last line of a classical Chinese poem, holds a place in China's internet landscape that few Western companies can match in their own markets. The poem, written by the Song dynasty poet Xin Qiji, describes someone searching through a crowd hundreds of times, only to turn back and find the person they sought standing in the dim candlelight. For a search engine, there could hardly be a more fitting origin story.

  Robin Li incorporated the company on the 18th of January 2000, along with Eric Xu. But the ideas behind it had been building for years. Li had already invented a search algorithm in 1996 that used hyperlinks to measure the quality of websites. That concept, which he called "link analysis," would influence one of Silicon Valley's most famous inventions. The company that grew from that algorithm would go on to become China's dominant search engine, a player in autonomous vehicles, an AI chip maker, and eventually the first Chinese firm admitted into a U.S.-based computer ethics consortium. How a software company in Beijing's Haidian District arrived at all of that is worth understanding.

• 2. The Idea Before the Company

  ›

  Robin Li joined IDD Information Services, a New Jersey division of Dow Jones and Company, in 1994. There he helped build software for the online edition of The Wall Street Journal and worked on improving how search engines sorted results. He stayed at IDD from May 1994 to June 1997.

  While still at IDD in 1996, Li developed the RankDex site-scoring algorithm. The central insight was that a website's quality could be measured by how many other sites linked to it. RankDex, launched that same year, was the first search engine to use hyperlinks as a quality signal. Li called his approach "link analysis."

  Two years later, in 1998, Google's founders applied a similar principle. Google founder Larry Page cited Li's work directly in some of his U.S. patents for the PageRank algorithm. Li later brought his RankDex technology with him when he built Baidu, making that early New Jersey research load-bearing for everything that followed.

• 3. Building the Business

  ›

  Baidu went public on Wall Street on the 5th of August 2005, using a variable interest entity structure based in the Cayman Islands. The Cayman Islands arrangement exists to allow foreign capital to invest in what is, under Chinese law, a restricted sector.

  In December 2007, Baidu became the first Chinese company to be included in the NASDAQ-100 index. That same year, the Chinese government granted Baidu a license that allowed it to function as a full news website, not just a search engine. It was the first Chinese search engine to receive such a license, giving it the ability to publish its own reports alongside search results.

  Baidu's primary revenue mechanism is its Tuiguang advertising platform, which works similarly to Google Ads. Advertisers pay each time a user clicks on their listing. Baidu's results pages have drawn criticism, however, because paid placements can fill the first two pages of results. People's Daily commented on the reliability concerns this raised in 2018. Advertisers using Baidu must hold a registered business address in China or certain East Asian countries, and Baidu's administrative tools are entirely in Chinese, adding a practical barrier for outside buyers.

  By May 2018, Baidu's market capitalization had reached US$99 billion.

• 4. Controversy and Crisis

  ›

  In April 2016, a 21-year-old student named Wei Zexi died after pursuing a cancer treatment he had found through Baidu. Wei had been diagnosed with synovial sarcoma, a rare form of cancer, and located a hospital through Baidu's paid search results. His family spent around 200,000 yuan, roughly US$31,150, on treatment at the Second Hospital of the Beijing Armed Police Corps before he died on the 12th of April 2016.

  The incident set off widespread online discussion in China. On the 2nd of May 2016, the Cyberspace Administration of China sent a team of investigators to Baidu's offices. One report at the time estimated that medical advertising accounted for around 30% of Baidu's ad revenue, much of it from for-profit hospitals connected to a network of entrepreneurs from the Putian region of Fujian province. Regulators subsequently required Baidu to add disclaimers to promotional health content and to create complaint channels.

  A separate controversy surfaced in January 2016 when it emerged that Baidu had sold control of its online community for people with hemophilia, part of its Tieba forum platform, to hospitals the community itself regarded as unqualified. Baidu announced on the 12th of January that all illness-related Tieba communities would stop commercial cooperation entirely and would be open only to authoritative public-interest organizations.

  In April 2019, apps developed by DO Global, a subsidiary that had been spun off from Baidu the previous year, were found to have secretly clicked on internet ads in the background of users' devices since at least 2016. One of the six known apps involved had been downloaded 50 million times from the Google Play Store. Google banned DO Global and more than 100 of its apps from the Play Store on the 26th of April 2019.

• 5. The Autonomous Vehicle Bet

  ›

  In April 2017, Baidu announced a project called Apollo, a self-driving vehicle platform intended to function as an open ecosystem for the autonomous driving industry. The platform covered vehicle hardware, software, and cloud data services. A $1.5 billion autonomous driving fund, intended to back as many as 100 projects over three years, launched in September 2017 alongside Apollo's open-source software version 1.5.

  Baidu partnered with Continental and Bosch on automated driving and connected vehicles in June 2017. By October 2017, the company was preparing to launch self-driving buses in China in 2018. In April 2022, Baidu received permits from Chinese authorities to provide the first driverless taxis to the public, operating within a 23-square-mile area in suburban Beijing from the 28th of April 2022. The Apollo RT6, a driverless vehicle planned to join the fleet, was unveiled in July 2022.

  As of April 2024, Baidu's Apollo Go ride-hailing service had completed six million rides across 11 cities using driverless vehicles. A fleet of more than 400 driverless cars operates in Wuhan alone. In July 2025, Baidu announced a partnership with Uber that would allow Apollo Go to operate outside the United States and mainland China.

• 6. Censorship and Government Relations

  ›

  The China Digital Times has described Baidu as the most active and restrictive online censor among Chinese search engines. Documents leaked in April 2009 from inside Baidu's monitoring department listed blocked websites and censored topics the company suppressed in accordance with government direction.

  In May 2011, activists filed suit against Baidu in the United States, arguing that its censorship practices violated the U.S. Constitution. A U.S. judge ruled that Baidu had the right to block content from its results under freedom-of-speech protections, dismissing the lawsuit.

  From 2017, Baidu began coordinating with the Chinese Ministry of Public Security and 372 Internet police departments to detect information flagged as "anti-government rumors," then flooding Baidu-connected web platforms and devices with official corrections. The company used natural language processing and big data to carry out this work. During the COVID-19 pandemic, Chinese regulators directed Baidu and other internet firms to conduct special supervision of disease-related news and information.

  In November 2022, the sustainability ratings firm Sustainalytics downgraded Baidu to "non-compliant" with United Nations Global Compact principles, citing the company's complicity in censorship. Despite that, the Chinese government has formally designated Baidu as one of its national champion corporations, and separately named it one of China's "AI champions" in 2018.

• 7. AI Ambitions

  ›

  In October 2018, Baidu became the first Chinese firm to join Partnership on AI, a U.S.-based consortium focused on computer ethics. The move came as the company was shifting substantial investment toward artificial intelligence across its product lines.

  Baidu publicly unveiled Ernie Bot, its large language model chatbot, in August 2023. A generative AI search chatbot based on the same underlying model, GenAI Ernie, launched in September 2023. A newer version, Ernie 4.0, followed in October 2023. On the 16th of March 2025, Baidu released two further models: ERNIE 4.5, described as a foundation model, and ERNIE X1, a reasoning model. Baidu stated that ERNIE X1 performs comparably to DeepSeek's R1 model at half the price.

  In January 2026, Baidu filed a listing application on the Hong Kong Stock Exchange for its semiconductor unit, Kunlunxin, extending the company's push to build the full hardware-to-application stack internally. In March 2021, Baidu had already secured a secondary listing on the Hong Kong Stock Exchange, raising $3.1 billion in what was described as the largest homecoming for a U.S.-traded Chinese company in Hong Kong since JD.com's listing the previous June.