Claude Code Opus 4.6 Now Defaults to 1M Token Context Window

Claude Code's Opus 4.6 model has been updated to default to a 1 million token context window. This change was observed by users without any formal announcement from Anthropic.

Key Details

According to user reports on r/ClaudeAI:

• Opus 4.6 in Claude Code now defaults to 1 million token context window
• Pricing remains unchanged from previous versions
• The change appears to be live and operational
• No official announcement has been made about this update

Context windows determine how much text an AI model can process in a single interaction. A 1 million token context window allows Claude to work with approximately 750,000 words of text, which is significant for codebases, documentation, and large files. This represents a substantial increase from previous Claude models that typically offered 200K token contexts.

For developers using AI coding assistants, larger context windows mean you can feed Claude entire codebases, multiple files, or extensive documentation in a single prompt. This enables more comprehensive code analysis, refactoring across larger code sections, and better understanding of project architecture.

The lack of official announcement suggests this might be a gradual rollout or testing phase. Developers should verify the context window availability in their own Claude Code instances.