No. Two people typing the same question into ChatGPT can get different answers, and one person can get different answers by asking twice. The reasons are documented by OpenAI, measurable by anyone with an API key, and they matter if your business is one of the things ChatGPT might name.
The short answer
The model does not look up a stored answer. It generates one, token by token, from a probability distribution, and OpenAI's developer documentation states that its "Chat Completions and Completions APIs are non-deterministic by default (which means model outputs may differ from request to request)". That is the model on its own, before search, memory or location touch the prompt.
Add those and there is even less reason to expect a single canonical answer. ChatGPT search rewrites your question before it searches. Memory feeds in what it knows about you. Your IP address sets an approximate location. Your plan decides which model answers. Two people asking "what is the best rank tracker" are not sending the same request, so the same reply would be the surprise.
Why two people get different answers
Sampling. Every answer is sampled. Developers can set a seed on the API, and OpenAI describes the result as a "best effort to sample deterministically", then adds that "determinism is not guaranteed" and that "there is a small chance that responses differ even when request parameters and system_fingerprint match, due to the inherent non-determinism of our models" (OpenAI, reproducible outputs with the seed parameter). The consumer app exposes no seed at all.
The batch your request lands in. Even at temperature zero, output is not stable. Thinking Machines Lab published the mechanism in September 2025: floating-point addition is not associative, and inference kernels are not "batch invariant", so a request's output depends on how many other requests the server was processing at the same moment. In their test, one prompt run 1,000 times produced 80 distinct completions (Defeating Nondeterminism in LLM Inference). An academic paper with no vendor behind it, Non-Determinism of "Deterministic" LLM Settings, ran five models across eight tasks ten times each under settings expected to be deterministic and reported "accuracy variations up to 15% across naturally occurring runs".
Retrieval. When ChatGPT searches, it "typically rewrites your query into one or more targeted queries" and, after reading the first results, "may send additional, more specific queries" (Searching the web with ChatGPT). Two runs can rewrite differently, fetch different pages and cite different sources. The same page says search results and citations "can be incomplete, outdated, or incorrect".
Location. From that page again: "ChatGPT may use an approximate location based on your IP address to provide relevant local results." OpenAI's own example is "restaurants near me" being rewritten to "top restaurants San Francisco". A VPN moves it. And "if memory is enabled, saved location information may also influence search results".
Memory. "When enabled, memory helps ChatGPT automatically remember useful context from your chats, files, and connected apps to personalize your experience" (Memory FAQ). That context is part of every answer generated while it is on. Temporary Chats "do not use existing memories or create new memories", which is the closest a person can get to the unpersonalised answer.
Model version and plan. The ChatGPT Free Tier FAQ says "the default model and available limits can change over time", and paid plans run different models from free ones. The answer you got in June came from a model that may no longer be serving anyone.
What actually varies and what does not
We have not measured user-to-user variance on ChatGPT, and the sources above are not our data. What we measured, on 22 August 2026, is the other axis: the same seven buying questions put to seven answer engines through our own scanner, 49 answers, about fourteen cents of provider cost. The full run is in the earlier post.
The engines disagreed far more than the questions did. Perplexity cited 51 distinct domains across the seven questions. Google AI Mode cited 20. ChatGPT sat between them at 27, and it was the one engine where a vendor's own domain out-cited every independent source: it named Ahrefs in six of the seven answers, and ahrefs.com was its most repeated citation, in three. Across all 49 answers the engines cited 139 distinct domains, no domain was cited by more than five of the seven engines, and 92 were cited by exactly one.
So the sources are unstable. The brands were not. Six brands were named by all seven engines: Profound, Peec AI, Otterly, Semrush, SE Ranking and Scrunch. On ChatGPT alone, Ahrefs appeared in six answers, Semrush in five, Otterly in four. When a brand turns up that often across questions and across engines, the wording of any single answer stops mattering. Which page gets the citation is noisy. Which brand gets named is a rate you can measure.
Sample size, stated plainly: seven questions, one category, one day. It shows the shape. It does not give you a percentage to quote.
What this means if you want ChatGPT to recommend you
Stop asking whether ChatGPT recommends you. The question has no single answer, and anyone who screenshots one chat and calls it proof either way has misread the mechanism. Ask instead how often it names you, and measure that the way you would measure a rank: the same questions, repeated, over time.
Being named is a rate. One answer says nothing. Ten answers to the same question over a month start to, because a single run cannot tell a brand named every time from a brand named a third of the time.
Sources are the noisy layer. The domain ChatGPT cites for a claim moves between runs. The brand it names moves less. If you are choosing between chasing a citation and being the thing that gets named, the second is the stable target.
Checking from your own account is the worst available instrument. Your memory profile, your location and your plan are all in the prompt. Use a Temporary Chat, or ask from outside your account entirely, and do it more than once.
How to check what ChatGPT says about your site
The cheap way is to open a Temporary Chat, ask the question a buyer would ask, note whether you are named and which sources are cited, and do it again tomorrow. Five repetitions cost nothing but time and tell you more than one.
If you want it done for you, our free check asks Google AI Overviews and ChatGPT with no account and reports who was named and which domains were cited. SEOBuilder is our own product, so weigh the recommendation accordingly. The ChatGPT engine page carries the per-domain numbers from the run above and is updated when we re-run it.
Whatever tool you use, run it more than once before you believe it. The answer varies. That is the finding, not a flaw in the measurement.