What this means for visibility
Blocking GPTBot opts out of training only. To appear in ChatGPT search answers, OAI-SearchBot must be allowed.
AI assistant · OpenAI
ChatGPT
OpenAI's own search index, built by OAI-SearchBot, combined with third-party search providers. Bing supplied results historically; in August 2025 reporting showed ChatGPT also drawing on Google results via SerpApi.
- Operator
- OpenAI
- Launched
- Nov 30, 2022 · web search Oct 31, 2024
- Search index
- OpenAI's own search index, built by OAI-SearchBot, combined with third-party search providers. Bing supplied results historically; in August 2025 reporting showed ChatGPT also drawing on Google results via SerpApi.
- Crawlers
- OAI-SearchBot — blocked by 7.6% of top sitesChatGPT-User — blocked by 9.6% of top sitesGPTBot — blocked by 17.9% of top sitesOAI-AdsBot — blocked by 4.2% of top sitesChatGPT Agent — blocked by 4.6% of top sites
- Referrer in analytics
chatgpt.comchat.openai.com- UTM tagging
- utm_source=chatgpt.com is appended to links in citations, so sessions can appear under that source even when the referrer is stripped.
- Ads
- Yes. Ads below answers for logged-in adult Free and Go users since 9 Feb 2026; 89 countries as of 21 Oct 2026. Plus, Pro, Business and Enterprise are ad-free.
- Citations
- Inline citations and a Sources panel; links carry utm_source=chatgpt.com.
- Official docs
- developers.openai.com
Usage, as stated
| As of | Metric | Value | Stated by | Source |
|---|---|---|---|---|
| Feb 2025 | Weekly active users | 400 million | OpenAI | technologychecker.io |
| Jul 2025 | Weekly active users | 700 million | OpenAI | openai.com |
| Oct 2025 | Weekly active users | 800 million | Sam Altman, DevDay 2025 | technologychecker.io |
| Feb 2026 | Weekly active users | 900 million | OpenAI | miraa.io |
| Feb 2026 | Paying consumer subscribers | 50 million | OpenAI | miraa.io |
| Aug 2026 | Weekly active users | 1 billion+ | OpenAI | miraa.io |
| Oct 2026 | Weekly active users | 1.2 billion | OpenAI | openai.com |
ChatGPT users over time (millions)
Questions
What search engine does ChatGPT use?
OpenAI's own search index, built by OAI-SearchBot, combined with third-party search providers. Bing supplied results historically; in August 2025 reporting showed ChatGPT also drawing on Google results via SerpApi.
Which crawlers does ChatGPT use?
ChatGPT relies on OAI-SearchBot, ChatGPT-User, GPTBot, OAI-AdsBot, ChatGPT Agent. Blocking GPTBot opts out of training only. To appear in ChatGPT search answers, OAI-SearchBot must be allowed.
How do I track ChatGPT traffic in analytics?
Clicks from ChatGPT arrive with the referrer chatgpt.com or chat.openai.com. utm_source=chatgpt.com is appended to links in citations, so sessions can appear under that source even when the referrer is stripped. Add it to an AI channel in GA4 using a source regex.
Does ChatGPT show ads?
Yes. Ads below answers for logged-in adult Free and Go users since 9 Feb 2026; 89 countries as of 21 Oct 2026. Plus, Pro, Business and Enterprise are ad-free.
Analysis using this data
Other AI engines
ChatGPT Atlas · Google AI Overviews · Google AI Mode · Gemini · Perplexity · Comet · Claude · Microsoft Copilot · Meta AI · Grok · DeepSeek · Le Chat · You.com · Brave Search (Ask Brave) · Kagi Assistant · DuckDuckGo (Duck.ai & Search Assist) · Amazon Rufus (retired)
How to cite this data
This dataset is free to use, including commercially, under Creative Commons Attribution 4.0. The one rule is attribution:
- Credit the source as “Kuldeep Paul, kuldeep.cc” wherever you use a figure, chart or table from it.
- Link to this page (https://kuldeep.cc/data/ai-search/chatgpt), not to the download file, so readers can check the source of every number.
- Include the date. These figures change; say “as of Oct 29, 2026” or link to the version you used.
- Mark changes. If you filter, recalculate or chart the data yourself, say so (“analysis based on data from…”).
- Cite the original source for single figures when you quote one reported number; it is linked in every row.
In running text: according to Kuldeep Paul's ChatGPT — AI search engine reference (kuldeep.cc). More in the methodology.
Paul, K. (2026). ChatGPT — AI search engine reference [Data set]. kuldeep.cc. https://kuldeep.cc/data/ai-search/chatgpt
Paul, Kuldeep. "ChatGPT — AI search engine reference." kuldeep.cc, 29 October 2026, https://kuldeep.cc/data/ai-search/chatgpt.
Paul, Kuldeep. 2026. "ChatGPT — AI search engine reference." Dataset. kuldeep.cc. Updated Oct 29, 2026. https://kuldeep.cc/data/ai-search/chatgpt.
@misc{paul2026chatgpt, author = {Paul, Kuldeep}, title = {ChatGPT — AI search engine reference}, year = {2026}, howpublished = {\url{https://kuldeep.cc/data/ai-search/chatgpt}}, note = {Dataset, CC BY 4.0, updated 2026-10-29} }
<a href="https://kuldeep.cc/data/ai-search/chatgpt">ChatGPT — AI search engine reference</a> (data: Kuldeep Paul, kuldeep.cc)