Context Window
Also called Context length
A context window is the token capacity available for a model’s current interaction. It limits how much supplied information and generated content can fit in that interaction, according to the model and service’s accounting rules.
[Anthropic]In practice · hypothetical example
An assistant loads a relevant page from a long manual instead of placing the entire manual in an already crowded conversation.
[Anthropic]A little deeper
Instructions, conversation history, and tool results can consume context. Information stored elsewhere is not automatically visible to a model just because the application retained it. [Anthropic]
A common mix-up
A larger context window is permanent memory.
Context capacity and storage across sessions serve different purposes. [Anthropic]
Similar terms, different emphasis
Compare Context Window & Memory →Does saving a file automatically put it in the next model input?
Sources & editorial notes
Evidence: supported. Primary-source support for this scoped entry; publication approved by the project owner.
- Context windows ↗ (opens in new tab)Anthropic · Publication date unknown
Relevant section: Understanding the context window
Last editorial review: 2026-09-13 by project-owner.
First observed in this corpus: Unknown.
Revision history
Revision 2 · Created 2026-09-13 · Updated 2026-09-13
Project owner approved the current content for publication. Existing evidence scope and limitations remain applicable.