Does ChatGPT use Google or Bing for search?

The short version

Source	How sure is it?	What the evidence is
Bing	Confirmed by OpenAI	OpenAI’s VP of Engineering, November 2024: “we use a set of services and Bing is an important one.” Many tests match ChatGPT citations to Bing results.
OpenAI’s own crawler (OAI-SearchBot)	Confirmed by OpenAI	OpenAI’s crawler documentation says OAI-SearchBot is “used to surface websites in search results in ChatGPT’s search features”.
Google	Reported, not confirmed by OpenAI	Tests in July 2025 got brand-new pages, indexed only by Google, to show up in ChatGPT. In August 2025 The Information reported that OpenAI had used Google results gathered by a scraping company, SerpApi.
Publisher partners	Confirmed by OpenAI	OpenAI has content deals with news publishers, whose articles can appear in answers.
Training data	Confirmed	When ChatGPT doesn’t search, it answers from what it learned in training. These answers have no live sources.

So the honest answer is “mostly Bing, plus its own crawler, and sometimes Google”. OpenAI has never published the full list or the share each source gets, and it can change without notice. Treat any article that gives you exact percentages with care.

What OpenAI has actually said

When ChatGPT search launched in late 2024, OpenAI said it was built with a mix of search technologies, including Microsoft’s Bing. A few days later, in a public Reddit AMA, OpenAI’s VP of Engineering put it plainly: “we use a set of services and Bing is an important one.” Microsoft is a major investor in OpenAI, so the Bing link is no surprise.

The other official source is OpenAI’s crawler documentation. It lists three user agents. OAI-SearchBot is for search: it finds and refreshes pages for ChatGPT’s search features. GPTBot collects content that may be used to train OpenAI’s models. ChatGPT-User fetches a page when a person asks ChatGPT to look at it. OpenAI says the robots.txt settings are independent, and that sites which block OAI-SearchBot “will not be shown in ChatGPT search answers, though can still appear as navigational links.”

That is the full official picture. OpenAI has not said what share of searches go to Bing, whether Google is used, or how it ranks the pages it gets back.

What tests and reports found about Google

In July 2025 several SEO practitioners ran the same kind of test. They made up a new word or wrote a new page, made sure only Google had indexed it (not Bing), and then asked ChatGPT about it. ChatGPT found it. Search Engine Roundtable collected these tests, including one by consultant Aleyda Solis, who concluded that ChatGPT was using Google’s search snippets for some answers.

A month later, The Information reported that OpenAI had been using Google search results collected by SerpApi, a company that scrapes search engines, mainly for questions about news, sports and markets. Google had reportedly turned down a direct request from OpenAI for access a year earlier. OpenAI did not confirm the details.

What this suggests: Bing does most of the work, and Google seems to fill gaps, especially for fresh or rare queries that Bing hasn’t indexed well. Other studies, including one by Ahrefs, found no sign that ChatGPT is “secretly Google”. Both can be true at once.

Why ChatGPT often doesn’t search at all

Many ChatGPT answers come from training data, with no search. ChatGPT decides to search when a question needs current or specific facts (“best mover in Austin with good reviews”, “opening hours”, “price of X”), or when the user turns on search. Studies of ChatGPT logs in 2025 also suggested it searches less often than it did at launch, though the numbers vary by study.

This matters because only searched answers show sources and send clicks. A training-data answer can still name your business, but it can’t link to you, and the person who reads it may simply search your name on Google or phone you. In your analytics that visit looks like Google or Direct, not ChatGPT. We cover how to count those customers in why AI attribution undercounts.

How the other AI assistants search

Assistant	Main search source
Microsoft Copilot	Bing (Microsoft’s own search engine)
Google Gemini and AI Overviews	Google Search
Perplexity	Its own crawler (PerplexityBot) and index, plus other providers; reports in 2025 said it also used scraped Google results
Claude	Anthropic’s web search tool, with its own crawlers; Anthropic doesn’t name an index provider for all searches

The practical point: if you are visible in both Google and Bing, you are covered for almost every assistant. Many small businesses check Google and never look at Bing.

What this means for getting your business into ChatGPT

1. Check that Bing has indexed you. Search site:yourdomain.com on bing.com. If key pages are missing, add your site to Bing Webmaster Tools (it can import from Google Search Console in a few clicks) and submit your sitemap.
2. Turn on IndexNow if your site supports it. IndexNow tells Bing about new and changed pages straight away. Many WordPress SEO plugins and Cloudflare offer it. We ping it every time we publish.
3. Allow OAI-SearchBot in robots.txt. Open yourdomain.com/robots.txt. If you see User-agent: OAI-SearchBot followed by Disallow: /, ChatGPT search can’t show you. Some security plugins and hosts block AI bots by default. You can block GPTBot (training) and still allow OAI-SearchBot (search).
4. Keep Google indexing healthy too. If ChatGPT uses Google to fill gaps, a page Google can’t index is a page ChatGPT is less likely to find.
5. Be on the pages AI cites. For local questions, ChatGPT often cites directories, review sites and “best of” lists rather than business websites. Make sure your name, address, phone and services match on them. Our guide to getting your business recommended by ChatGPT walks through this.
6. Write pages that answer one question plainly. A page titled after the question, with the answer in the first two sentences, is easy for any search system to match. A quick site audit for AI search shows the gaps.

How to check whether it’s working

Two separate checks, because they answer different questions:

• Does ChatGPT name you? Ask it the questions your customers ask, with search on, once a month, and note whether you are named and whether your site is cited. Our free ChatGPT visibility checker does one check for you.
• Does ChatGPT send you customers? In GA4, look for the source chatgpt.com (ChatGPT tags many links with utm_source=chatgpt.com). Our guide on tracking ChatGPT traffic shows the report. Remember that GA4 can’t see the people who read an answer and then phoned you.

Which AI Sent does the second check automatically: it records visits from ChatGPT, Gemini, Perplexity, Claude and Copilot, ties them to the leads and bookings they became, and asks new customers how they found you, so the phone calls count too.