How to Identify the Sources Behind ChatGPT?

With the growing use of generative AI tools like ChatGPT, understanding where the information provided by these models comes from has become essential for brands and SEO/GEO professionals.

When a user gets an answer from ChatGPT, is it generated out of thin air? Is it based on press articles, Reddit posts, or Wikipedia entries? Or does it pull information directly from live web searches?

In this article, we'll take a closer look at the main sources used by ChatGPT, how to identify them manually, and how to save time by using the Qwairy tool to track your presence across LLMs.

Reminder: ChatGPT and SearchGPT Rely on Different Sources

ChatGPT is OpenAI's large language model (LLM) and includes several versions, with the main ones being:

• GPT-3
• GPT-3.5
• GPT-4

On the other hand, SearchGPT is a hybrid LLM.

Hybrid LLMs access the web in real time using techniques like RAG (Retrieval-Augmented Generation).

Thanks to a partnership with Microsoft, SearchGPT leverages Bing search results.

As of April 2025, SearchGPT announced it now handles nearly 1 billion searches per week.

1.1 ChatGPT's training Corpus

Every AI model is trained on a specific dataset, commonly referred to as a training corpus.

The standard version of ChatGPT generates its answers based on a massive training corpus, which includes:

• Wikipedia – widely used for general knowledge and factual information
• Royalty-free books – from initiatives like Project Gutenberg
• Open-access scientific papers – such as those from arXiv and PubMed
• Public forums – including Reddit, Stack Overflow, and Quora
• Open-source content – like GitHub repositories and technical documentation

Below is an overview of the training sources used for GPT-3: Source: Wikipedia

FYI Common Crawl is a non-profit organization that crawls the web and makes the data publicly available.

That said, LLM datasets evolve quickly. In France, for example, a partnership was signed between several media outlets—including lemonde.fr—and ChatGPT. As a result, lemonde.fr is now a regular source for SearchGPT.

Let's dive into that now.

1.2. Partnerships and licensed data

Since 2024, OpenAI has signed numerous licensing agreements to use content from a wide range of media outlets and websites.

To save you time, here's a list of publishers that have partnered with OpenAI:

• Le Monde (France): First French media to sign an agreement with OpenAI. The partnership gives ChatGPT access to Le Monde articles to improve the reliability of its responses, with direct links to the sources cited.
• News Corp (United States, United Kingdom, Australia): Agreement with a potential value of $250 million, including publications such as The Wall Street Journal, The Times, The Sun and The New York Post.
• The Washington Post (United States): Strategic partnership enabling ChatGPT to provide summaries, quotes and direct links to original Washington Post articles.
• The Financial Times (UK): Partner in OpenAI's "Preferred Publisher" program, offering increased visibility in ChatGPT.
• Axel Springer (Germany): Agreement covering titles such as Bild, Die Welt and Politico Europe.
• Prisa Media (Spain): Partnership with publications such as El País, Cinco Días and El HuffPost.
• The Atlantic and Vox Media (United States): Licensing agreements for the use of their content in OpenAI products.
• Associated Press (United States): License agreement signed in July 2023, allowing use of its archives for training AI models.
• Reddit: Partnership signed in May 2024, offering OpenAI real-time access to Reddit content via its API. In return, Reddit benefits from AI-powered features and an advertising partnership with OpenAI.
• Stack Overflow: Agreement allowing OpenAI to use Stack Overflow data to improve its AI models, while providing Stack Overflow with AI-based tools for its users.
• SearchGPT: Prototype launched in July 2024, integrating partner press sources such as Le Monde, The Atlantic, News Corp, Prisa Media and Axel Springer to provide up-to-date answers with links to the original articles.

1.3. Real-time web access

When the SearchGPT feature is enabled, the model can perform live searches via Bing to:

• Retrieve up-to-date information (e.g., news, recent data)
• Cite sources directly from Bing search results

This approach is known as RAG, or Retrieval-Augmented Generation.

Retrieval-Augmented Generation (RAG) is an AI technique that enhances response accuracy by retrieving relevant documents from a knowledge base and incorporating them into the generated output. It allows the model to ground its answers in real, external content.

1.4. Other specific sources

ChatGPT also uses other ways to get information:

• Structured databases such as Wikidata.
• Synthetic data created by OpenAI to refine models. OpenAI also reuses data from people who use its tool.

How can I manually identify the sources used by ChatGPT?

2.1. Using ChatGPT on a private browser

When using ChatGPT, here's how to do it:

• Ask a question.
• Look for notes or quotes at the bottom of the answer.
• You can also ask directly: "What are your sources for this answer?"

⚠️ Warning: sometimes ChatGPT will mention "I base my answer on my internal knowledge" if no web research has been done.

2.2. Analyze SearchGPT results

In SearchGPT, citations are much more visible. Links typically come from the top results on Bing.

However, the pages shown in Bing search results don't always match exactly what ChatGPT references.

Based on multiple tests we've run, it appears that ChatGPT relies on Bing SERPs from several weeks earlier rather than real-time results.

2.4. Observation via Bing

Since Bing feeds SearchGPT, analyzing the Bing SERP allows you to anticipate which pages might be picked up.

3. Limits of manual search

• No total transparency: except for displayed quotations, it's impossible to know with certainty the source of a piece of information.
• Stochastic answers: the same question may give different answers.
• Irregular updates: ChatGPT's database is only updated during new training sessions.

How to automate source analysis with Qwairy

Qwairy is a SaaS solution that allows you to monitor:

• Your brand's visibility across ChatGPT, Perplexity, Gemini, Claude, and other LLMs
• The queries where your brand is mentioned on LLMs
• The sources used by LLMs to generate responses

In practical terms, Qwairy analyzes the answers provided by LLMs to thousands of targeted questions and generates:

• A dashboard showing whether and where your brand is mentioned
• A source report listing the websites cited by the language models
• A competitive analysis to see who's outperforming you

Qwairy gives you direct access to all the sources used by each LLM:

You can even see in detail which pages are cited:

And select the LLM you prefer to find out its sources (here we select ChatGPT):

5. Conclusion

The world of SEO is evolving towards a world where GEO (Generative Engine Optimization) is taking on a predominant role.

Knowing which sources ChatGPT uses for its answers has become a key skill for:

• Improving your content strategy.
• Develop brand awareness.
• Optimize backlinks in a targeted way.

✅ By combining intelligent manual monitoring with powerful tools like Qwairy, you'll be able to regain control over your visibility in LLMs and capture valuable traffic.

Ready to take action? Test your visibility on Qwairy and find out in just a few clicks where and how ChatGPT is talking about you.