Claude Opus 5

Claude Opus 5

Quick answer: Claude Opus 5 is Anthropic's flagship model in the Opus 5 generation, achieving the highest Quality Rubric Index (1.18× the model average) on the Legora BAR legal benchmark. It consistently leads on long-horizon agentic tasks where sustaining judgment across large, complex document records is critical.

At a Glance

Where Claude Opus 5 leads

• Highest overall quality on Legora BAR — 1.18× above the model average
• Strongest performance on long-form legal tasks (full matter deliveries, multi-week scope)
• Consistent quality across short, medium, and long difficulty levels
• Top-tier overall quality in the Legora harness across 28 legal practice areas

Where it lags

• Highest median latency per case in the Legora BAR evaluation (slowest in the set)
• Higher cost per case than Grok 4.5 and Claude Sonnet 5