# Even Google’s AI puts ChatGPT ahead of itself

Kesterley study, data October 2026. https://kesterley.com/reports/ai-assistants/

More and more companies ask an AI assistant which AI assistant to buy. So we asked ChatGPT, Gemini and Claude the same questions in eight buying situations and recorded 1,008 answers. The three rivals agreed on one thing: ChatGPT. It was the assistant each of them mentioned most, and Google’s Gemini mentioned it more often than it mentioned Gemini.

## Executive summary

- **Even Google’s AI puts ChatGPT ahead of itself.** Gemini mentioned ChatGPT in 332 of its 336 answers and itself in 228, less often than ChatGPT, Claude and Copilot. When it named both, ChatGPT came first in two answers out of three.
- **ChatGPT puts ChatGPT first.** Asked in general terms, ChatGPT named itself first in 67% of its answers, and in 59 answers it recommended itself in the first person.
- **Only Claude says it is one of the options.** In 22 answers Claude told the reader it was one of the products it was comparing. ChatGPT and Gemini never did.
- **Your office software has already chosen.** For a company on Microsoft 365, every answer from every assistant included Copilot. On Google Workspace, every answer included Gemini.
- **Grok is not on the list.** Not one of the 1,008 answers mentioned Grok or its maker, xAI.

## Share of answers mentioning each assistant (six general situations, from memory)

| Assistant | Asked ChatGPT | Asked Gemini | Asked Claude |
|---|---|---|---|
| ChatGPT | 98% | 100% | 99% |
| Claude | 89% | 94% | 98% |
| Gemini | 86% | 70% | 84% |
| Copilot | 81% | 78% | 73% |
| Perplexity | 29% | 16% | 19% |
| Amazon Q | 7% | 11% | 4% |
| Meta AI | 0% | 9% | 12% |
| Mistral | 1% | 6% | 11% |
| Glean | 5% | 4% | 7% |
| Grok | 0% | 0% | 0% |

## Gemini’s own answers (336 answers, all eight situations, both modes)

- ChatGPT: mentioned in 332 answers (99%)
- Claude: mentioned in 310 answers (92%)
- Gemini: mentioned in 228 answers (68%)
- Copilot: mentioned in 243 answers (72%)
- Perplexity: mentioned in 50 answers (15%)
- Amazon Q: mentioned in 27 answers (8%)
- Meta AI: mentioned in 20 answers (6%)
- Mistral: mentioned in 15 answers (4%)
- Glean: mentioned in 19 answers (6%)
- Grok: mentioned in 0 answers (0%)

When a Gemini answer named both, ChatGPT came first in 152 of 228 (general situations: 151 of 185). Claude: ChatGPT before Claude in 202 of 303. Exploratory.

## Named first (six general situations, from memory, exploratory)

| Named first | Asked ChatGPT | Asked Gemini | Asked Claude |
|---|---|---|---|
| ChatGPT | 67% | 41% | 54% |
| Claude | 2% | 18% | 19% |
| Gemini | 2% | 2% | 3% |
| Copilot | 25% | 32% | 18% |
| Perplexity | 3% | 7% | 5% |

ChatGPT recommended itself in the first person in 59 of 336 answers. Claude said it was one of the options in 22 answers; ChatGPT and Gemini never did. Office suites: Copilot in every Microsoft 365 answer, Gemini in every Google Workspace answer. Grok or xAI: 0 of 1,008 answers.

## Pre-registered tests

- Self-preference: not confirmed. ChatGPT −3 points (−6 to −1), Claude +1 (−3 to +6), Gemini −15 (−21 to −8). Every sentence counted: ChatGPT −1, Claude +6 (+3 to +10), Gemini −15. Threshold 15 points.
- Partners and investors: ChatGPT and Copilot +6 (0 to +11); Claude and Amazon Q −5 (−9 to −2).
- Office suites: confirmed in full.

## How we measured

ChatGPT, Gemini and Claude via official developer interfaces, October 2026. Eight buying situations (six general, two naming the office suite), six wordings each, five repeats from memory (720 answers) and two with web search (288 answers). Stability r = 0.84 and 0.85. Methodology: https://kesterley.com/methodology/

Kesterley is a research and advisory firm. We measure what AI assistants such as ChatGPT, Gemini and Claude tell buyers about companies and markets, and help leadership teams decide what to do about it.

Cite as: Kesterley (2026). Which AI recommends which AI: AI assistants for business. Data October 2026. kesterley.com/reports/ai-assistants