AI Concepts·intermediate
Context window
How much the AI can see at once. When it fills up, the early stuff gets forgotten.
The context window is how much text the AI can see at once — your full conversation, plus anything you've attached.
When it fills up, older content gets dropped or compressed. That's why:
- Long chats start forgetting earlier details.
- Pasting a huge document can crowd out your actual question.
- Starting a fresh conversation sometimes beats continuing an old one.
Different models have different window sizes, measured in tokens. Claude's is currently one of the largest available — but it's not infinite. And even inside the window, models pay more attention to the beginning and end than the middle.