03/13/2026 11:37:55ChatGPT’s Default and Premium Models Search the Web in Different Ways
Many people use ChatGPT every day to find answers on the internet. But most users do not know that different versions of ChatGPT may search the web in very different ways. Because of this, two users asking the same question may receive answers that include different websites as sources.
A recent study by Writesonic found something very interesting. The study showed that ChatGPT’s default model and its premium model often use different strategies when they search the web before giving an answer.
In this article, we will explain this research in very simple language so that anyone can understand how these models work and why it matters.
Two ChatGPT Models Compared
The study looked at two versions of ChatGPT:
GPT‑5.3 Instant – the model that most users get when they log into ChatGPT.
GPT‑5.4 Thinking – the advanced model available to premium users.
Both models can search the internet to gather information before writing an answer. However, the research showed that they do not search the web in the same way.
When both models were asked the same questions, they often showed answers that cited completely different websites.
In fact, the overlap between the sources used by the two models was only about 7%. This means that 93% of the time, the models used different websites as sources.
This is a very big difference.
How the Default Model Searches the Web
The default model, GPT-5.3 Instant, usually performs one broad search query when it tries to find information.
Think of it like a student who goes to a search engine, types one question, and then reads the top few articles that appear.
Because of this behavior, the default model often cites third-party websites such as:
tech blogs
review sites
news articles
guides and tutorials
Some websites were cited many times in the research. These included:
Forbes
TechRadar
Tom’s Guide
These types of websites publish many articles about software tools, technology, and business topics.
Because GPT-5.3 reads these articles, it often uses them as sources when answering questions.
According to the research, about 32% of the sources used by GPT-5.3 were blog posts or articles.
This means the default model depends a lot on media websites and review content.
How the Premium Model Searches the Web
The premium model, GPT-5.4 Thinking, works in a different way.
Instead of doing only one search, it performs many smaller searches.
On average, the model ran 8.5 separate searches for each question.
Each search looked for a very specific type of information.
For example, if someone asked about CRM software, the model might search like this:
CRM pricing information
CRM product features
CRM user reviews
CRM comparisons
But the most interesting part is that GPT-5.4 often searches inside specific websites.
It does this using something called a “site:” operator.
For example, the search might look like:
site:hubspot.com pricing
site:salesforce.com CRM features
site:attio.com CRM pricing
This tells the system to search only inside a certain website.
The research found that GPT-5.4 used the site operator 156 times out of 423 searches.
No other tested ChatGPT model used this method.
Premium Model Often Chooses Brand Websites
Another big difference is the type of websites each model cites.
The premium model sends many of its citations to brand websites.
For example, if someone asks about CRM tools, GPT-5.4 may directly check websites like:
HubSpot
Salesforce
Attio
Instead of reading blogs about these companies, the model often goes directly to the official website.
The study found that 56% of GPT-5.4 citations pointed to brand websites.
This is very different from GPT-5.3, where only 8% of citations were brand websites.
So the premium model trusts first-party information more.
More Focus on Pricing Pages
The premium model also looks at pricing pages much more often.
Pricing pages are the pages where companies show how much their products cost.
The research found something surprising.
Across 49 conversations:
GPT-5.3 cited only 4 pricing pages
GPT-5.4 cited 138 pricing pages
This is a huge difference.
It shows that GPT-5.4 tries to gather very specific details, such as product prices, plans, and subscription levels.
But there is also a problem.
Some companies do not show prices directly on their websites. Instead, they ask visitors to contact the sales team.
When pricing information is hidden like this, the premium model may have less information available.
This can make comparisons harder.
Comparison Questions Show the Biggest Difference
The research also tested comparison questions.
For example:
“HubSpot vs Salesforce vs Pipedrive”
In these tests, the difference between models became very clear.
The default model never cited brand websites for comparison questions.
Instead, it cited blogs, reviews, and comparison articles.
But the premium model did the opposite.
For the same questions, GPT-5.4 cited brand websites 83% to 100% of the time.
This shows how strongly the premium model prefers official sources.
Do ChatGPT Sources Match Google Results?
The researchers also wanted to know something else.
They asked a question:
Do the websites cited by ChatGPT also appear in search engine results?
To test this, they used SerpAPI.
SerpAPI allows researchers to see what websites appear in search engines like:
Google
Microsoft Bing
They compared the websites cited by ChatGPT with the websites ranking in these search engines.
The results were very interesting.
Default Model
For GPT-5.3:
47% of the cited websites also appeared in Google search results
This means the default model often chooses websites that already rank well in search engines.
In simple terms, if a website ranks high in Google, it has a good chance of being cited by the default ChatGPT model.
Premium Model
For GPT-5.4, the results were very different.
About 75% of the cited websites did NOT appear in Google or Bing results for the same search query.
This suggests that GPT-5.4 may not depend as much on normal search rankings.
Instead, it may rely more on targeted searches inside specific websites.
However, researchers say this idea still needs more testing to confirm.
Why This Is Important for Businesses
These findings are very important for companies and website owners.
Many businesses now want their brands to appear inside AI answers, not just search engines.
But this study shows that different ChatGPT models may prefer different types of content.
For the Default Model
If you want visibility in the default ChatGPT model, it may help to have:
articles written about your brand
mentions on review websites
coverage in media publications
comparisons written by bloggers
Because GPT-5.3 reads these websites frequently.
For the Premium Model
If you want visibility in the premium model, your own website becomes more important.
You should focus on creating clear pages, such as:
product pages
pricing pages
feature explanations
documentation pages
Because GPT-5.4 often goes directly to brand websites.
Measuring Traffic from ChatGPT
There is another interesting detail from the research.
Many of the URLs cited by ChatGPT included a special tag in the link:
utm_source=chatgpt.com
This tag helps website owners track where visitors come from.
If someone clicks a link from ChatGPT, analytics tools can show that the traffic came from ChatGPT.
This means brands may soon be able to measure how much traffic AI tools send to their websites.
What May Happen in the Future
ChatGPT technology is changing very quickly.
New models are often released, and their behavior may also change over time.
The patterns seen in this research may not stay the same forever.
Future models might:
Combine both strategies
Rely more on trusted sources
Search more deeply across the web
As AI tools become more advanced, they may develop new ways of finding information online.
You can also read: Google AI Overview Citations Are Changing: What It Means for SEO
Final Thoughts
The study by Writesonic shows something very important.
Even inside the same platform, different AI models may search the web in completely different ways.
The default model, GPT-5.3 Instant, often relies on:
blog articles
media websites
review platforms
Meanwhile, the premium model, GPT-5.4 Thinking, often prefers:
official brand websites
product pages
pricing pages
Because of these differences, the sources shown in AI answers can change depending on which model a user is using.
For businesses, marketers, and website owners, this means visibility in AI tools may require multiple strategies, not just traditional SEO.
As AI continues to grow, understanding how these systems gather information will become more and more important.