Claude Opus 4.5 (latest)

Claude Opus 4.5 is Anthropic's frontier reasoning model designed for complex software engineering, agentic workflows, and long-horizon computer use. Built as the culmination of what Anthropic calls a trilogy of releases, it brings strong multimodal capabilities and improved robustness to prompt injection. The model supports an effort parameter that lets developers trade off speed, depth, and token usage depending on task requirements, enabling flexible deployment across varied workload types. Its architecture enables coordinated multi-agent setups and advanced tool use, making it well-suited for autonomous research, multi-step planning, and sustained computer interactions like browser or spreadsheet manipulation. Anthropic positions it as the best model for coding, agents, and computer use, with evaluations across challenging benchmarks including ARC-AGI-1 and WebArena testing.

The release brought a dramatic shift in cost structure, with input and output pricing reduced by roughly two-thirds compared to the previous generation. This move makes frontier-level capabilities more accessible while maintaining state-of-the-art performance on software engineering tasks. Anthropic's internal engineering assessments showed Opus 4.5 scoring higher than any human job candidate in the company's history on their most challenging evaluation. The model delivers substantial gains in structured reasoning, execution reliability, and alignment over prior Opus generations, alongside reduced token overhead that improves efficiency on long-running tasks. These advancements position it for professional development environments, enterprise automation, and complex debugging scenarios where sustained accuracy and multi-step planning matter most.