Anthropic has raised the context window for Claude Sonnet 4 to one million tokens on the Anthropic API, Amazon Bedrock, and soon Google Cloud Vertex AI. This is five times larger than before, letting users process entire codebases or large sets of research documents in a single run. The change is primarily for developers working with extensive source code or those who need to summarize large volumes of text. The one million token context is currently in public beta for customers with Tier 4 or custom API limits.
The expanded context window comes with steeper pricing. For requests over 200,000 input tokens, Anthropic charges $6 per million tokens, double the usual rate. Output tokens cost $22.50 per million, up from the standard $15. Anthropic points to prompt caching and batch processing as ways to cut costs, with batch processing potentially lowering expenses by up to 50 percent.
