Claude Opus 4.5 (latest)

Claude Opus 4.5 is positioned as Anthropic's flagship Claude-tier model, with an independent aggregator describing it as built for deep reasoning, coding, and long-horizon agent tasks. That positioning places it at the top of the Claude family and signals an emphasis on sustained multi-step problem solving rather than short-form chat. The thinking variant label visible in third-party benchmark tables also implies Anthropic is exposing a deliberate chain-of-thought mode alongside a standard non-thinking mode, giving users a choice between raw response and slower, more carefully reasoned output.

Independent measurement reinforces the flagship framing. Artificial Analysis gives Claude Opus 4.5 an Intelligence Index of 29.1 for the thinking variant and 23.7 for the non-thinking variant, a sizeable gap that suggests the thinking mode contributes meaningful reasoning lift on this benchmark family. Mirrored OpenRouter Design Arena preference scores for sub-categories such as 3d design, Android-native layouts, ASCII art, and code categories cluster in the 1166 to 1258 range, indicating consistent human-preference competitiveness across diverse design and coding tasks. Together these signals point to a model best suited to complex agentic coding sessions and design-related generation, while leaving room for users to toggle reasoning depth depending on the cost or latency trade-off they want.