Anthropic’s Claude Sonnet 4 in Amazon Bedrock Expanded Context Window

Anthropic’s Claude Sonnet 4 in Amazon Bedrock is launching today with a significantly expanded context window in public preview. The context window has been increased from 200,000 to 1 million tokens, representing a 5x expansion. This enhancement allows Claude to process and reason over much larger amounts of text in a single request, opening up new possibilities for comprehensive analysis and generation tasks.

This expanded context window for Sonnet 4 brings many benefits to customers. For large-scale code analysis, users can now load entire codebases, including source files, tests, and documentation, enabling Sonnet 4 to understand project architecture, identify cross-file dependencies, and suggest improvements that account for the complete system design. In document synthesis, the model can now process extensive document sets like legal contracts, lengthy research papers, large datasets, or technical specifications in a single API call, analyzing relationships across hundreds of documents while maintaining full context. Additionally, this expansion allows for the creation of more sophisticated context-aware agents that can maintain coherence across hundreds of tool calls and multi-step workflows, including complete API documentation and interaction histories.

The expanded context window for Claude Sonnet 4 is now available in public preview in Amazon Bedrock in US West (Oregon), US East (N. Virginia), and US East (Ohio) AWS regions. Prompts over 200,000 tokens will incur approximately twice the token price for input and 1.5 times for output. To get started with the expanded context window for Claude Sonnet 4, visit the Amazon Bedrock console.