Instead of classic search engines like Google or Bing, AI is increasingly being used for research. At the end of 2025, as part of a Bitkom survey, half of people in Germany said they at least occasionally used chatbots instead of search engines – among 16 to 29 year olds it was even two thirds. Google has also reacted to this development and, in addition to the classic search results, now offers an AI mode and AI overviews. But where do the answers that the AI tools provide come from?
Analysis finds clear differences
AI models rely on a variety of sources to provide the most precise answers possible. The software company Blinq evaluated a total of 250,000 responses to set prompts between January 1st and June 30th, 2026. The goal was to take a closer look at the sources of three of the most widely used AI tools for information discovery, including ChatGPT, Google AI Overviews, and Perplexity. The central result: Around two thirds of all cited sources come from company websites, i.e. from company blogs, official websites and landing pages.
A look at the most frequently cited sources shows that YouTube and Reddit are clearly ahead with around 15 percent each. This is followed by Wikipedia with 9 percent and Linkedin with 7 percent. Among the German news sites, Welt is in the lead with 17 percent, Handelsblatt has around 12 percent and Chip has just under 9 percent. This means that although company websites provide the largest share of content, when it comes to individual, particularly frequently used addresses, platforms with real user discussions and reviews make the difference.
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AI tools do not have their own expertise
The analysis also shows clear differences between the individual tools. ChatGPT relies particularly on Reddit, Wikipedia, World, Linkedin, Google and Image. As Basic Thinking notes, the frequent appearance of the two Axel Springer media is probably no coincidence, as OpenAI has entered into a partnership with the publisher. Google AI Overviews noticeably often cites user-generated content. YouTube takes first place here, but doesn’t appear in the top sources at ChatGPT. Instagram, Handelsblatt and OMR reviews also play a role. Perplexity also relies heavily on YouTube and Reddit, but also includes Linkedin, Instagram, Handelsblatt, Chip, Wikipedia as well as OMR and Stern.
Other studies have also analyzed the source usage of AI search engines. Researchers at SE Ranking focused on the search for health information using Google’s AI Overviews. They also came to the conclusion that YouTube was cited most frequently with 4.43 percent of all sources – more often than any official health authority or medical institution. The problem: Content can be published on YouTube without professional review and can provide misleading or incorrect recommendations to people with questions about diagnoses and possible therapies. An investigation by The Guardian also found that Google AI Overviews can produce potentially harmful answers.
Caution is advised when conducting AI research
In connection with their analysis, the Blinq researchers make it clear that large language models are “not knowledge databases, but word probability machines”. They have no knowledge of their own, but compare live web data with external sources. AI-generated search results should therefore always be critically examined. Much of the underlying information comes from company websites, Reddit discussions, or YouTube videos. Particularly when it comes to health questions or other sensitive topics, it is advisable to carefully check the sources provided.
