What is a context window?
A context window is the amount of text an AI language model can look back on and use when it writes a reply. It works like the model's working memory. It is separate from the large body of data the model was trained on.
A larger context window lets a model handle longer and more complex prompts. A smaller one can limit how long a prompt the model can take in, or how well it stays coherent over a long conversation. Anthropic's glossary calls the window the model's working memory.
Background from ai notis, not part of the news. Checked against its sources on 4 Oct 2026.
Our sources
- Glossary · Anthropic