What Is a Knowledge Cutoff? AI Training Dates Explained

Definition

Knowledge cutoffA knowledge cutoff is the date after which an AI model has no training data. The model can't know about anything newer, such as a product launch or a price change, unless it searches the web while it answers. Each model has its own cutoff, and newer model versions move it later.

How Searchable measures this

Searchable tracks Claude Lite and Grok Lite alongside the standard Claude and Grok engines. The Lite engines run the same models without web search, so you can compare what a model says about your brand from training data alone with what it says after searching.

How a knowledge cutoff works

A large language model learns from a fixed collection of text gathered up to a certain date. Training then stops, and the model's knowledge freezes at that point. Anything that happened afterward, such as a renamed product or a new competitor, isn't part of what the model learned.

Each model has its own cutoff. When a vendor releases a new model version, it usually comes with a later cutoff, and older models keep their original one.

Reliable knowledge cutoff vs training data cutoff

Some vendors publish two dates. Anthropic's model documentation lists a "reliable knowledge cutoff," the date through which the model's knowledge is most extensive and reliable, and a separate training data cutoff for the broader range of data used.

The difference matters for recent events. Topics from the last few months before a cutoff are thinly covered online, because people haven't finished writing about them yet. A model may know a product exists but have little detail about it.

How web search works around the cutoff

AI engines get past their cutoff by searching. When an engine searches the web before answering, it reads current pages and writes from them. This is called grounding, and it's why an engine can describe last week's news.

Engines don't search for every question, though. In Searchable's July 2026 test of 1,374 prompts, ChatGPT searched on 89% of them, but Claude searched on only 48%. On comparison and reputation questions, Claude answered from memory more than 85% of the time, according to the Claude Lite study.

What a knowledge cutoff means for your brand

Every AI answer about your brand comes from one of two places. A searched answer comes from the pages the engine reads at that moment. A memory answer comes from what the model learned before its cutoff. The two can describe you differently.

Memory answers are where cutoff problems show up:

  • A brand founded after the cutoff may not exist as far as the model knows.
  • A rebrand or new product name may be missing, so the model uses the old one.
  • Old pricing or retired features can be repeated as if they're current.

Outdated facts aren't the same as hallucinations, though the reader can't tell them apart. An outdated fact was true once. A hallucination never was.

How to find a model's knowledge cutoff

Check the vendor's documentation. The major AI companies list a cutoff on each model's page, and the date can differ between models from the same company.

Asking the model directly is less reliable. It only knows what its training data says about it, which may be incomplete or out of date. For how ChatGPT's training data is put together, see where ChatGPT gets its data.

How to work with knowledge cutoffs

Treat the two kinds of answer as separate jobs:

  1. For searched answers, keep current facts on pages engines can find and read, such as pricing and integrations. Changes there can show up within days of a crawl.
  2. For memory answers, build accurate coverage over time on your own site and on third-party pages. It reaches the model only when a new version is trained, which can take months.

Check the memory answer on its own. If you only test engines that search, you'll miss what the model believes about you when it doesn't.

Frequently asked questions

Each ChatGPT model has its own cutoff, which OpenAI lists in its model documentation, and it changes with every new model. ChatGPT also searches the web for most questions. In a July 2026 test of 1,374 prompts, it searched on 89% of them, so many answers include information from after the cutoff.

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GroundingGrounding in AI means tying a language model's answer to specific source material, such as live search results or a company's own documents, so the model isn't relying only on what it learned in training. A grounded answer can point to its sources, which is why AI search engines show citations.AI hallucinationAn AI hallucination is a confident but false statement from an AI model, such as a price your product never had, a feature it doesn't offer, or a source that doesn't exist. Hallucinations happen because language models generate the most likely-sounding answer, and they don't check whether it's true.Retrieval-augmented generation (RAG)Retrieval-augmented generation (RAG) is a technique where an AI model first searches a set of documents for passages that match a question, then writes its answer from those passages. Because it looks things up at answer time, the model can use up-to-date information and point to where it came from.
Large language model (LLM)An AI model trained on large amounts of text to predict and generate language. LLMs are the engines inside ChatGPT, Claude, Gemini, and most AI search tools.
Agentic searchAgentic search is when an AI system runs its own research loop instead of a single search. It plans queries, reads the results, decides what's still missing, and searches again until it can answer. Deep research modes in ChatGPT, Gemini, Perplexity, and Claude work this way, and they read far more pages than one search returns.Content freshnessSignals that tell search engines and AI systems a page is current, such as a visible update date and recent data.

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