Does ChatGPT use Google or Bing? What the evidence shows

Does ChatGPT use Google or Bing?

Start with what the companies themselves say. OpenAI’s help documentation for ChatGPT search says it sometimes works with third-party search providers, rewriting your question into one or more search queries and sending those to the provider. For Enterprise and Edu workspaces it is explicit: “Currently, the only third-party search provider we use for Enterprise and Edu workspaces is Bing.” For other plans it doesn’t publish a full list.

Microsoft confirmed its side at Build in June 2026, when it introduced Web IQ, a set of AI grounding APIs for the web: “The APIs in Web IQ already power grounding experiences for Microsoft Copilot and ChatGPT.” On top of that, OpenAI runs its own crawler, OAI-SearchBot, which it describes as being “used to surface websites in search results in ChatGPT’s search features”.

What neither company says is how much of an answer comes from each source. That gap is where the “ChatGPT uses Google” claims come in.

What did the “ChatGPT uses Google” tests actually find?

Two tests from August 2025 are behind most of the current answers to this question, and they point in different directions.

The first, published by Semrush on 6 August 2025, describes a small experiment: a page about an invented term was made reachable only by Google, and ChatGPT later cited it. A repeat of the test suggested that the paid version of ChatGPT used Google while the free version didn’t. The article is candid about its limits: “We don’t know exactly how often or in what circumstances ChatGPT uses Google instead of Bing.” It is a handful of runs, not a measurement of share.

The second, published by Ahrefs on 20 August 2025, went the other way at scale. It took 118,931 search queries that ChatGPT generated, ran them in Google and checked whether ChatGPT’s sources showed up there. Only 6.82% were in Google’s top 10, 9.85% in the top 20 and 16.61% anywhere in Google’s results. Its conclusion: ChatGPT “doesn’t appear to be ‘secretly Google-powered’” and most likely draws on several sources. Neither test measured Bing.

Put together, the two tests fit one picture rather than contradicting each other: ChatGPT can reach Google results in some cases, but Google is not where most of its sources come from. Press reports in August 2025 also described OpenAI pulling some Google results through a third-party scraping service; neither OpenAI nor the service confirmed it.

When does ChatGPT actually search the web?

Not every time you ask. ChatGPT answers a lot of questions straight from its trained knowledge - a snapshot of the web frozen when the model was built - and only searches when it needs something current or wants to cite a live source. So there are two parts at work: the trained one that recalls what it already learned, and the search step that looks things up in real time.

That split matters for visibility. A brand can live in the model’s trained memory and still vanish the moment ChatGPT switches to search - or the reverse. The part you can move within weeks, with fresh content and indexing, is the search step. When it runs, ChatGPT pulls a handful of pages from its search providers and its own crawl, then summarises and cites the ones it trusts most. If your page isn’t findable there, it can’t be one of them.

You can watch this happen. Ask ChatGPT about last week’s news and it will search, showing small source links; ask it to define a common term and it usually answers from memory, with no links. Those citations are the sign that the search step just ran.

Why does Bing still matter for your brand?

Because it is the one provider that is confirmed on both sides, and the one you can check yourself. If Bing barely indexes your site, you are missing from at least one of the pools ChatGPT draws from when someone asks “what’s the best [your category]”, and Microsoft Copilot reads the same stack. Competitors who are indexed there get the chance to be cited in your place.

What has changed since this article first ran is the “only” part. Treating Bing as the single gate to ChatGPT overstates what anyone has published. Treating it as optional is the opposite mistake: a strong Google position doesn’t carry over on its own, as the 6.82% overlap above shows.

Which search engine does each AI assistant use?

“AI visibility” isn’t one channel. Each assistant leans on a different back-end, so being visible in one says little about the others. The state of what is publicly documented, as of October 2026:

• ChatGPT - Bing (named by OpenAI and Microsoft), OpenAI’s own crawler OAI-SearchBot and other providers OpenAI doesn’t fully list; Google results in some cases, according to the tests above
• Microsoft Copilot - Microsoft’s own web grounding, the same stack Microsoft says serves ChatGPT
• Perplexity - its own crawler, PerplexityBot
• Google Gemini, AI Overviews and AI Mode - Google Search; for AI Overviews and AI Mode, Google’s documentation requires a page to be indexed and eligible to show with a snippet
• Claude - Brave Search, which Anthropic added to its list of subprocessors in March 2025

What should you actually do about it?

The good news: most of this is hygiene you already know from Google, just applied to more than one index.

• Verify your site in Bing Webmaster Tools (free, with a one-click import from Google Search Console) and submit your sitemap.
• Check that Bing actually indexes your key pages - Google indexing them doesn’t mean Bing does.
• Don’t block OAI-SearchBot in robots.txt if you want to appear in ChatGPT search results. Blocking GPTBot, OpenAI’s training crawler, is a separate decision.
• Keep your Google indexing healthy too: Gemini, AI Overviews and AI Mode depend on it, and ChatGPT appears to reach Google in some cases.
• Earn mentions on the sources assistants cite for your category, so there is something for them to find whichever index they read.
• Track whether assistants actually mention and cite you, per engine, so you see what moved and where.

The bottom line

The honest answer to “Google or Bing?” is “Bing for sure, other sources too, Google sometimes”. Bing is the part that both companies confirm and the part you can fix in an afternoon. The rest changes faster than anyone documents it, which is why measuring your presence in the answers beats guessing at the plumbing behind them.

If ChatGPT names a competitor and skips you, the index is rarely the whole story. What the model does with the pages it finds is covered in how AI chatbots decide which brands to recommend.