Context Window
How much text a model can read at once.
Why it matters
Context window determines how much information an AI model can process at once. A small context window means the model forgets earlier parts of a long conversation or document. A large one lets it handle entire codebases, legal contracts, or book-length content in a single prompt.
When comparing AI tools, context window size directly affects what tasks they can handle without losing track of important details.
How it works
4 stepsRelated terms
From the glossaryFrequently asked questions
Who chooses what goes into the context window?+
The application developer decides what to include: the system prompt, conversation history, retrieved documents, and the user message. Once the window is full, older content must be removed or summarised.
What happens when the context window is full?+
The model can no longer see earlier parts of the conversation. Applications handle this by summarising old turns, using retrieval to pull in only the most relevant past content, or starting a fresh context.
Does a bigger context window mean better quality?+
Not necessarily. Very long contexts can dilute attention and reduce the model's focus on the most relevant information. Quality also depends on what is placed in the window.
See the tools that use it.
The fastest way to understand Context Window is to see it inside real products. Browse hand-reviewed tools that put it to work, each one checked by a person before it was listed.
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