Knowledge Cutoff in plain English.

A knowledge cutoff is the date after which an AI model has no built-in knowledge of world events, because its training data was collected up to that point and no further. Ask a model about something that happened after its cutoff and, without web browsing enabled, it will either say it doesn't know or — worse — hallucinate a plausible-sounding but wrong answer. Frontier labs have shortened the gap between cutoff and release considerably: early GPT models had cutoffs over a year old at launch, while 2026-era models ship with cutoffs just a few months old. Live web search, now built into ChatGPT, Claude, and Gemini by default, works around the cutoff for current-events questions by fetching fresh information at query time rather than relying on memorized training data — but it's worth remembering that any model's default, non-browsing answer still reflects a fixed moment in the past.