Claude Opus 4.1 is an upgraded version of Claude Opus 4 that delivers enhanced performance across several key areas, particularly in agentic tasks, real-world coding, and reasoning capabilities. The primary difference lies in its significantly improved coding performance, achieving 74.5% on SWE-bench Verified compared to Opus 4’s previous results. This represents a substantial leap in the model’s ability to handle complex, multi-step programming challenges that mirror real-world software development scenarios.
The improvements in Opus 4.1 extend beyond just coding benchmarks. The model demonstrates enhanced in-depth research and data analysis skills, with particular strengths in detail tracking and agentic search capabilities. Companies like GitHub have noted that Opus 4.1 excels in multi-file code refactoring, while Rakuten Group has observed its precision in identifying exact corrections within large codebases without introducing unnecessary changes or bugs. This level of surgical precision makes it particularly valuable for debugging and maintenance tasks in enterprise environments.
What sets Opus 4.1 apart is its ability to maintain the hybrid reasoning architecture of its predecessor while delivering measurably better results across most capabilities. Windsurf reported that Opus 4.1 shows roughly one standard deviation improvement over Opus 4 on their junior developer benchmark, representing a performance leap comparable to the jump from Sonnet 3.7 to Sonnet 4. This means developers can expect more accurate, context-aware solutions for complex engineering tasks, better autonomous research capabilities, and improved handling of long-horizon projects that require sustained attention and precision across thousands of steps.