AI glossary
Knowledge cutoff
The date after which a model has no information from its training data.
A model only knows what was in the data it was trained on. Anything that happened after its cutoff — new products, prices, laws, events — is unknown to it unless it can search the web or you provide the information.
If you ask about recent events without giving sources, a model may hallucinate or give outdated answers. Check whether your assistant has web search turned on.
Example: Anthropic says Claude Opus 5.5 has reliable knowledge up to June 2026, and Claude Haiku 4.5 up to February 2025. Ask Haiku about a model released in 2026 without web search and it will not know it.
In practice
- For recent news, prices or laws, use web search or give it the source.
- If you do not know your assistant’s cutoff, look it up on the model’s page.
- Some model pages distinguish reliable knowledge from the training-data date.
Why it happens, in how LLMs work.
