What Is a Context Window in AI?
A context window is the maximum amount of text — measured in tokens — that an AI model can consider at one time, including your prompt and its response. A larger context window lets a model work with longer documents, bigger codebases and longer conversations without losing track.
Why context windows matter
Anything outside the context window is invisible to the model. A small window forces you to chop up long inputs; a large one lets the model read an entire contract, book or codebase at once and reason across all of it.
Context windows across models
Models differ widely in context length. Claude and Gemini are known for very large windows, which makes them strong for long-document work. Choosing the right model for the input size is part of getting good results.
See it in action
Allecta applies context window directly: it queries several leading AI models in parallel and synthesizes one cross-verified answer with consensus scoring — so you get the benefit of this concept without building anything.
Try Allecta free →Context Window: FAQ
What is a token?
A token is a chunk of text, roughly ¾ of a word on average. Context windows and pricing are usually measured in tokens.
Which AI has the largest context window?
It changes as models update, but Gemini and Claude have led on context length. For very large inputs, compare current limits or use a tool that routes to the best model.