News · anthropic · claude · long-context · pricing
Claude Sonnet 4.5's 1M-token context window graduates from beta
Draft — pending editorial review
Anthropic moved Claude Sonnet 4.5's 1M-token context window from beta to general availability on July 2, 2026. The beta header requirement is removed. Prompts above 200K tokens bill at premium rates — $6 input and $22.50 output per million tokens — doubling effective input cost for full-window workloads.
Anthropic promoted Claude Sonnet 4.5’s 1M-token context window to general availability on July 2, 2026, per the context windows documentation. The context-1m beta header is no longer required; all API traffic can address the full window.
The pricing structure
The window is tiered. Prompts up to 200K tokens bill at the standard $3 input / $15 output per million. Prompts above 200K bill the entire request at the long-context rate of $6 input / $22.50 output per million tokens (rates verified July 2, 2026).
That cliff shape matters for pipeline design: a 210K-token prompt costs more than twice a 195K-token prompt on input. Retrieval pipelines that can compress below the boundary should; the premium tier is priced for workloads that genuinely need single-pass reasoning over massive context — codebase-scale analysis, long-document synthesis, extended agent sessions with full history.
Competitive position
GA closes most of the context gap with Gemini 3 Pro, whose 1M-token window has been standard since its November 2025 launch with a gentler tier boundary ($4 input above 200K vs Anthropic’s $6). For pure long-document work, Gemini remains cheaper at the top of the window; Sonnet’s case rests on its agentic-coding lead. Both patterns are priced out in our head-to-head.
The Claude Sonnet 4.5 model page reflects GA status in its spec table as of July 2, 2026.