Claude Opus 4.5 is a frontier-scale model from Anthropic designed for demanding reasoning, coding, and long-context analysis workloads. It delivers highly helpful and precise responses, with particularly strong instruction-following and comprehension that make it well-suited for complex software, research, and legal tasks. The model also provides strong creative writing capabilities and can navigate sensitive conversations with solid empathy, though it typically trades speed and cost efficiency for depth and reliability compared to newer mid-sized models.