ChatGPT’s Thinking Mode Alters Brand Citation Patterns

ChatGPT’s high-reasoning mode effectively operates as a distinct search engine for brand visibility, according to a joint analysis by Semrush and Kevin Indig. The study revealed that when the AI shifted into deeper thinking, it cited entirely different domains and executed nearly five times as many web searches compared to its minimal reasoning counterpart.

By the numbers. Only 25.6% of cited domains overlapped between the two reasoning modes when responding to the same prompts. That means nearly three out of every four sources changed when ChatGPT moved from its quick, Instant-style answers to its more deliberate Thinking-style responses.

The deep-thinking mode also pulled from a broader pool. Citation rates jumped from 50% in minimal reasoning to 68% in high reasoning. Answers that included citations also drew on more sources, averaging 4.5 citations per response versus 2.6. High reasoning triggered 1,130 web searches across the test set, compared to just 245 for minimal reasoning.

Reddit lost significant ground. Its citation share fell from 15% to 7% when high reasoning was activated. Similarly, user-generated content and review sites dropped from 14.3% to 6%. Meanwhile, government and academic sources saw a sharp rise, climbing from 1.9% to 8.8%. Official documentation and support pages also grew, from 12.4% to 17.5%.

Comparison prompts drove the most searches. At the comparison stage, high reasoning averaged 24 sub-queries per prompt, versus just 5.5 for minimal reasoning. Average citations also peaked there, at 9.8 per high-reasoning response compared to 5.8. For instance, a CRM comparison might trigger separate searches for pricing, integrations, security, support pages, and documentation before ChatGPT assembles its final answer.

Early citations lasted longer in the high-reasoning mode. It was more likely to carry a brand from early research into later buying questions. In four of the 20 buyer journeys tested, a brand cited at the problem stage still appeared at the selection stage. Minimal reasoning showed no full-journey persistence whatsoever. High reasoning also reused the same domains more often within a single answer, with the same domain appearing multiple times in 51 of 100 high-reasoning responses, versus 26 of 100 minimal-reasoning responses.

Finance saw the biggest citation jump. The lift varied by category: Finance rose 28 percentage points in high reasoning, health and lifestyle gained 24 points, B2B SaaS climbed 16 points, and consumer tech barely moved, rising only 4 points. Even though high reasoning ran more sub-queries for consumer tech prompts than for any other category, it often landed on the same brands and sources as minimal reasoning.

Why we care. Your content may surface in quick ChatGPT answers but disappear when users ask more complex questions. Visibility depends on whether your pages, documentation, and third-party references can appear across the smaller, targeted searches ChatGPT runs before it delivers a high-reasoning response.

About the data. Semrush and Indig tested 100 prompts across 20 buyer journeys in B2B SaaS, finance, consumer tech, and health and lifestyle. Each prompt ran once in minimal reasoning and once in high reasoning. The analysis tracked citation rate, cited sources, and fan-out queries. The report concluded that only 25% of cited sources overlap between ChatGPT’s different reasoning modes.