Context Window

What Is Context Window?

A context window is the AI model's working memory. It defines how much text the model can see at once when generating a response. Older language models had very small context windows (maybe 1,000 tokens), forcing conversations to be broken into short exchanges. Modern models have dramatically larger context windows: GPT-4 Turbo supports 128,000 tokens, Claude supports up to 200,000 tokens.

Larger context windows enable new capabilities: analyzing entire documents, maintaining longer conversations without losing context, and processing multiple files simultaneously. They're particularly valuable for document analysis, code review, summarization, and research tasks where you need the model to understand the full scope of information.

Context window size affects both capabilities and costs. Larger context windows cost more to process because the model must attend to more tokens. Efficient use of context—avoiding redundant information, structuring prompts clearly, and using compression techniques—becomes important as context usage grows.