ChatGPT Is Using Google Search – We Tested It

Final month, Abhishek Iyer ran a pointy experiment:

He created a brand-new nonsense time period, received it listed solely in Google, after which requested ChatGPT about it.

ChatGPT returned an ideal abstract — even though Bing had by no means seen the web page.

That check received our consideration.

So we ran our personal.

We invented a brand new faux search engine optimisation time period, NexorbalOptimization, revealed a devoted web page on Backlinko, and made certain solely Googlebot may crawl it.

Then we waited.

The outcomes confirmed what Abhishek — and a handful of others — have began to suspect:

ChatGPT Plus is utilizing Google Search information. Not simply Bing.

Right here’s how we ran the check, what we discovered, and what this implies for the way forward for AI search visibility.

Step 1: Create a Time period That Doesn’t Exist

We made up a brand new search engine optimisation buzzword: NexorbalOptimization.

It had:

• Zero mentions on-line
• No search quantity
• No overlap with actual phrases, acronyms, or model names

We constructed a brand new web page on Backlinko with fake-but-professional sounding content material explaining what “NexorbalOptimization” supposedly is.

Right here’s the reside URL: https://backlinko.com/nexorbaloptimization

Step 2: Let Google In (and Block Everybody Else)

Subsequent, we up to date our robots.txt file with the next:

# Enable Googlebot to entry the particular web page
Person-agent: Googlebot
Enable: /nexorbaloptimization
# Block all different bots from that web page solely
Person-agent: *
Disallow: /nexorbaloptimization

We additionally made certain this URL wasn’t included in our public sitemap.xml file.

That meant:

• Googlebot may crawl and index the web page
• Bing, Perplexity, DuckDuckGo, Claude, and different bots have been blocked
• The web page was invisible to public crawlers and AI instruments, until they have been utilizing Google

We manually submitted the URL to Google Search Console and waited for indexing.

Step 3: Watch for Indexing, Then Ask ChatGPT

As soon as the web page was reside, it took just a few hours to get listed in Google:

We confirmed that it nonetheless wasn’t listed in Bing:

Or DuckDuckGo:

Then, we examined a immediate in several LLMs / fashions:

ChatGPT Plus (short-term chat, with net searching) discovered our web page and quoted it word-for-word:

ChatGPT Free (with net searching, not logged in) couldn’t discover something:

Neither may Claude 4 Sonnet:

Apparently, Perplexity was the one different one which managed to search out it:

The Outcomes

Solely ChatGPT Plus and Perplexity’s Free plan returned a legitimate reply based mostly on the Backlinko web page.

All different fashions both:

• Returned nothing
• Mentioned the time period didn’t exist
• Or made one thing up with out referencing the web page

This confirmed two issues:

1. Google was the one search engine that knew in regards to the time period
2. The AI responses mirrored the precise phrasing, construction, and ideas from our made-up web page

Why This Issues

There’s been hypothesis for months that ChatGPT particularly is perhaps counting on extra than simply Bing.

OpenAI has an official partnership with Microsoft.

ChatGPT’s default searching mannequin is commonly described as utilizing Bing.

However these experiments inform a special story.

Right here’s what’s turning into more and more clear:

1. ChatGPT Plus is indexing Google Search

Particularly when different engines haven’t seen the web page.

2. search engine optimisation visibility in Google straight influences AI solutions

In case your web page doesn’t rank in Google, ChatGPT possible received’t “see” it — no matter whether or not you rank in Bing or not.

3. Google is the trusted supply of fact for LLMs

Not as a result of it’s said — however as a result of it’s listed sooner, deeper, and extra fully.

What This Means for search engine optimisation within the Age of AI

This check, and others prefer it, reveal one thing vital:

AI search visibility is turning into an extension of Google’s dependable index and search visibility.

You’re not simply optimizing to seem in a SERP.

You’re optimizing to be pulled right into a ChatGPT reply field.

Or a Perplexity paragraph.

Or a Gemini-generated comparability.

If Google doesn’t index you — many AI instruments received’t floor you.

That makes indexation and crawl entry much more strategic than earlier than.

Why LLM Visibility Nonetheless Begins with Google (And The right way to Monitor It)

For those who’re making an attempt to grasp the place your model exhibits up in AI-generated content material, it’s essential to begin with a easy fact:

Google’s index is the muse layer for many LLMs.

Whilst instruments like ChatGPT, Claude, and Perplexity generate solutions on the fly, they’re pulling from a mixture of:

• Crawled net outcomes (usually from Google-indexed pages)
• Structured information
• Excessive-authority model mentions

In case your content material isn’t listed — or isn’t rating — it’s invisible to an important LLMs.

That’s why conventional search engine optimisation fundamentals nonetheless matter:

• Crawlability
• Quick indexing
• Content material structured for semantic readability
• Proudly owning your model queries and product phrases

Wish to observe your presence in AI instruments?

You’ll want greater than only a rank tracker.

Considering Forward

As LLMs turn out to be extra influential within the discovery course of, you’ll wish to begin monitoring how your model exhibits up throughout instruments — not simply in SERPs.

Meaning discovering a device (or set of instruments) that:

• Can scale along with your model and content material footprint
• Tracks citations, summaries, and AI-generated publicity
• Is clear about what it’s monitoring and the way

For those who’re already utilizing Semrush, their AI SEO Toolkit is a stable start line.

For enterprise groups managing a number of properties or worldwide markets, Semrush Enterprise AIO provides extra depth.

Backside line:

LLM visibility is a brand new floor space. And the sooner you begin monitoring it, the higher positioned you’ll be to affect it.

Wish to Run the Check Your self?

1. Invent a faux phrase
2. Create a web page with distinctive content material
3. Undergo Google Search Console
4. Block all different bots by way of robots.txt
5. Watch for indexing
6. Immediate ChatGPT (Plus with searching) with a easy query
7. See what it says

This sort of sting-test isn’t simply intelligent — it’s revealing how the AI discovery layer is definitely working.

Shoutout

Large credit score to Abhishek Iyer for working the unique experiment that sparked this.

You possibly can learn his breakdown here.

We simply adopted the path — with a barely sillier time period.