ChatGPT-User is what OpenAI sends when a person (or a Custom GPT) causes ChatGPT to open a web page. OpenAI says it is not used for automatic crawling, is not the switch for ChatGPT search, and that robots.txt may not apply because the fetch is user-initiated. Source: Overview of OpenAI Crawlers.
That makes it the most useful "bot" on the list for a marketer who cares about demand, and the worst one to confuse with ads.
A ChatGPT Ads click can land with oppref and convert through the Measurement Pixel or Hardal's OpenAI Ads destination. A ChatGPT-User hit means the model retrieved your HTML to answer a question. The human may never hit your JS tag. You still want the log.
How it shows up
UA includes ChatGPT-User (example ChatGPT-User/1.0; +https://openai.com/bot). IPs: openai.com/chatgpt-user.json. Volume is bursty. Fastly clocked ChatGPT's fetcher bots at 98% of all real-time AI retrieval requests, which our marketer crawler post covers in full. Do not average them into GPTBot.
GA4's AI Assistant channel (May 2026) counts human clicks from assistants, not these origin fetches.
What to report
- Same-day alerts on ChatGPT-User to
/pricing,/demo,/contact, comparison URLs - Path list: which answers ChatGPT is currently grounding
- Split vs OAI-SearchBot (index) vs GPTBot (training) vs paid ChatGPT Ads
If fetchers are high and searcher coverage is zero, people are pasting URLs or the model is retrieving without you being in the search index. Fix the index with OAI-SearchBot, not with more ads spend.
robots.txt
You can still write a User-agent: ChatGPT-User block. OpenAI's own wording is that it may not bind. Search opt-out is OAI-SearchBot. Training opt-out is GPTBot. Do not use ChatGPT-User as a substitute for either.
How Hardal measures it
Hardal names it as a fetcher under OpenAI on the AI Visibility pipeline. isvisible.ai includes ChatGPT-User in its live UA check. For what to do when the spike lands, AI crawler traffic for marketers.