Anthropic Expands Claude Sonnet 4 Context Window to 1 Million Tokens

Anthropic has announced a significant expansion to the working memory of its AI models, a move framed as part of the ongoing AI coding wars among major players. The company has increased the context window of Claude Sonnet 4, one of its most capable models, to 1,000,000 tokens. This represents a fivefold increase from its previous context window and is designed to help users analyze far larger bodies of text and code in a single API request. The announcement underscores how critical context windows have become as a differentiator in enterprise AI tooling, where customers want models that can reason over long documents and sizable codebases without fragmenting tasks. The Verge reported that Anthropic sees this as a key way to compete with OpenAI, Google, and other industry players The Verge.”