ITG NowHome › AI glossary › Context window
What is a context window?
Short answer
A context window is the amount of text an AI model can keep in mind at one time while it answers.
- Category Models
- Also called context length, context limit
- Updated 20 Oct 2026
Context window, explained simply
Think of it as the model's short-term memory or desk space. Everything in your chat and any files you add must fit on that desk.
If a chat grows too long, older parts may get dropped or forgotten.
A bigger window lets you paste a long report or a whole book and ask questions about it.
On ITG Now, our AI models page and news stories note context window sizes when models are compared.
Related terms
TokenLLMAI memoryRAGContext engineeringHallucination
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Questions people ask about Context window
What happens when the context window is full?
The tool may cut off older text or ask you to start a new chat.
Does a bigger context window mean a better model?
Not always. It means the model can read more at once, but quality still matters.