Claude Sonnet 4.6 (Adaptive Reasoning, Max Effort)

Claude Sonnet 4.6, developed by Anthropic and released on February 17, 2026, is an AI model featuring Adaptive Reasoning and Max Effort capabilities. The model achieves an intelligence index of 51.7 and a coding index of 50.9. Performance metrics indicate an output speed of 67.675 tokens per second with a time to first token of 53.09 seconds. Pricing is set at $3.75 per million input tokens and $15.00 per million output tokens, resulting in a blended rate of $6.56 per million tokens. Benchmark results include 0.875 on GPQA, 0.3 on HLE, 0.468 on SciCode, 0.565986394557823 on IFBench, 0.706666666666667 on LCR, 0.53030303030303 on TerminalBench Hard, and 0.757309941520468 on TAU2.