Does ChatGPT Know This Week’s Swiss Supermarket Deals?
Only partly. Without web search, ChatGPT answers from training data that stops months before your question, so this week’s deals cannot be in it; with search it can find current pages, but OpenAI’s help pages (October 2026) say results and citations can be incomplete, outdated or wrong. At the three big Swiss supermarket chains new deals usually start on Thursday and run until the following Wednesday, so always check an answer against its source and the two validity dates.
Rappn compares the current promotions of 7 Swiss retailers, updated daily: free, no subscription.
See this week’s deals, freeOnly partly, and it depends on how the assistant is working. Without web search, ChatGPT answers from what it learned in training: according to the OpenAI Help Center, viewed on 13 October 2026, its answers do not include events after the model’s cutoff date, so this week’s deals cannot be in there. With search it can find current pages, but the same source warns that results and citations can be incomplete, outdated or incorrect. Because Swiss deals change every week, always check the answer against the source and the two validity dates.
Updated October 2026. Sources, viewed on 13 October 2026: Anthropic (Claude Help Center: web search; models; web search tool; MCP announcement); Google (AI Overviews); modelcontextprotocol.io; OpenAI (Help Center: web search, accuracy, shopping, connected apps; models; MCP servers); start days: the chains’ press releases and trade press (January 2025 and January 2026) and readings of the chains’ websites on 6 and 25 September 2026.
Does ChatGPT know this week’s deals?
That depends on how it is answering at that moment. Without web search, ChatGPT uses only what it learned in training: according to OpenAI, its answers do not include events after the model’s cutoff, unless tools such as search are used. That date is called the knowledge cutoff, the point up to which the training data runs. As of October 2026, the model pages of Anthropic and OpenAI put it between April and June 2026 for their newest models, so a deal that started later cannot be in the model’s memory.
With search switched on, the picture changes: according to OpenAI, ChatGPT can search automatically when a question needs current information, and cite the pages it used. But the same guide warns that results and citations can be incomplete, outdated or incorrect, and another OpenAI page says the model may be unable to read a site because of technical problems, paywalls or robots.txt rules.
For deals that last only a few days, this matters more than for a recipe: OpenAI itself advises using ChatGPT as a first draft, not as a final source. That applies to what is on offer today, and to any other assistant.
The offers view shows the current promotions of seven Swiss retailers with the unit price, so you can compare them with an AI assistant’s answer.
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Where does an AI assistant get its information?
| Source | How current | Possible errors |
|---|---|---|
| The model’s memory | Stops at the knowledge cutoff, months before your question | Can present a past period as current: OpenAI warns that dates and facts can be wrong |
| The assistant’s web search | As current as the page it picks: the assistant decides whether and what to search | Can use old or incomplete pages, cite a source that does not support the answer or fail to read a site (OpenAI’s cautions) |
| Chain websites and leaflets | Valid for the printed period; on 6 September 2026 one chain had two weekly leaflets online at once | The expired week or the next one can be mistaken for the current week |
| Google’s AI summaries (AI Overviews) | Summarise pages found by Search; also available in Switzerland, in German, French and Italian | Google warns that AI responses may include mistakes |
Sources: the providers’ pages (viewed on 13 October 2026) and the guide to promotion start days; the possible errors are inferred from these sources, not from a test.
Why are deals hard for AI?
Because deals (called “Aktionen” in German) are data that expires within days, comes from different sources and has its conditions in the small print.
- They change every week. At the three big chains new deals start on Thursday and run until the following Wednesday: one chain moved to this rhythm in the week of 21 January 2025, the other two on 5 February 2026. Two discounters run two waves a week, from Monday and from Thursday; another chain starts on Monday and ends on Saturday, and another starts on Tuesday with no end date (readings of 25 September 2026, in the guide to the days promotions start). A list copied on Wednesday evening is already out of date on Thursday morning.
- A comparison takes many searches. According to Anthropic’s developer documentation, a simple factual question usually takes one to three searches, while a comparison across several items can take ten or more; OpenAI explains that ChatGPT rewrites the question into targeted searches. Comparing the deals of several chains is the second case.
- The conditions are in the details. Some deals carry no end date and run “while stocks last”; a few chains publish deals that apply only in one region or canton; some promotions are multiplied loyalty points rather than a price cut (see how Swiss Aktionen work). What counts is the line with the dates and notes, not just the price.
- Where you are matters. Some chains have the same name in neighbouring countries, with their own deals, and ChatGPT may use an approximate location taken from your IP address: if local results show the wrong area, OpenAI advises writing your city or postcode in the question. Check that the site is Swiss and the prices are in francs.
How to check an AI answer about deals
Four steps are enough, and they build on the providers’ own advice.
- Ask for the source and the dates. For example: “Which page or leaflet is each deal from? Give me the link, the country of the site and the two validity dates.” If a result looks wrong, OpenAI suggests asking ChatGPT to search again with a specific source, date or location.
- Open the cited page. Check the product, the pack size, the price per kilo or litre and the period; OpenAI recommends checking when the source was published or updated; Google advises checking important information in more than one place.
- Compare the dates with today. The weekday is only a hint, the period decides: the deal may have expired, be about to expire or not have started yet. Also look at “while stocks last”, regional notes and the currency.
- Confirm where you shop. Before you make a special trip for a deal, check the price on the chain’s website or app, or on the shelf.
A more robust method is to bring the data yourself: copy the deals from the chains’ pages and ask the assistant to sort them by store or by dish. That way the data that expires stays under your control, and the AI only does the sorting. For lists, see the guide to an AI grocery list.
AI assistants connected to current data: what changes
What changes is where the data comes from: instead of relying on its memory or a web search, the assistant queries a service you have connected, and the answer is as current as that service, which depends on how often whoever runs it updates it. Depending on the provider, the link is called a connector, an app or a plugin. The open standard behind many of these links is the Model Context Protocol (MCP): its site describes it as an open-source standard for connecting AI applications to external systems and names ChatGPT and Claude among those that support it; Anthropic introduced it on 25 November 2024. How it works is explained in what is an MCP server.
A connection does not replace checking: the assistant still summarises. What remains to check is the coverage (chains and cantons), the last update and the validity dates. OpenAI says it neither develops nor verifies custom MCP servers, advises connecting one only if you know and trust the application behind it, and suggests official servers run by the service providers.
How to see this week’s deals today
The most direct route is the source: open the deals pages or leaflets of the chains near you, read the two dates and compare the price per kilo or litre. Comparison tools show several chains side by side: see the guide to grocery price comparison apps.
Rappn is a free Swiss app (iOS and Android) that compares the current promotions of seven Swiss retailers and turns receipts into a spending overview. In the offers view you see them side by side, with unit prices and a canton filter, updated daily as the chains publish them; you can also follow the products you buy and get an alert when one goes on offer. Rappn covers groceries, not rent, insurance or taxes. Rappn is building an AI assistant for groceries: you can join the waitlist.
Updated: .
Why Rappn?
Rappn is an independent grocery price comparison app in Switzerland, with no commercial agreements with any retailer. Our comparisons are truly independent.
- 100% free: no subscription, no hidden costs
- Neutral: no commercial agreements with Migros, Coop, Aldi, Lidl, Denner, Aligro, or Otto’s
- Updated daily, as soon as the chains publish their deals
- The chains’ deals in one place: search, filter, compare, no subscription
- Meal planner in the Kitchen tab: plan the week, send the ingredients to your list
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Frequently Asked Questions
Does ChatGPT know Swiss supermarket promotions?
Only partly. Without web search ChatGPT answers from training data that stops at the model’s knowledge cutoff (between April and June 2026 for the newest models, according to the model pages of Anthropic and OpenAI as of October 2026); with search it can find current pages, but OpenAI warns that results and citations can be incomplete, outdated or incorrect. Always check the source and the two validity dates.
Why does AI give wrong prices?
A wrong price can come from an old or incomplete page, a citation that does not support the answer, or one period mistaken for another. OpenAI writes that search results and citations can be incomplete, outdated or incorrect and that the prices in its product listings come from third-party providers and may be updated with a delay; Google writes that AI responses may include mistakes.
Which day do new promotions start?
At the three big Swiss supermarket chains on Thursday, valid until the following Wednesday; two discounters run two waves a week, from Monday and from Thursday; another chain starts on Monday and ends on Saturday, and another starts on Tuesday with no end date (the chains’ press releases of 2025 and 2026, and readings of their websites on 25 September 2026).
What is a connector (MCP)?
A connector links an AI assistant to an outside service that it can query directly, instead of relying on its memory or a web search. MCP (Model Context Protocol), introduced by Anthropic on 25 November 2024, is an open standard for these links and, according to the project’s site, is supported by ChatGPT and Claude, among others.
Where can I see this week’s promotions of several chains?
On each chain’s website or leaflet, reading the two validity dates. To see the current promotions of seven Swiss retailers side by side, you can use the free Rappn app, which updates them daily as the chains publish them.