Anthropic launches Claude Opus 5 with efficiency, safety improvements
Anthropic PBC today rolled out a large language model called Claude Opus 5 to its chatbot service and developer platform.
The company says that the LLM approaches the output quality of its top-end Mythos 5 algorithm in many areas, but costs significantly less.
Anthropic hasn’t made Mythos 5 publicly available. The company instead sells access to a scaled-down version of the LLM called Fable 5 that shares many of its features, but poses a smaller cybersecurity risk. Anthropic compared Fable 5 to Opus 5 across 13 benchmarks. It says that the latter algorithm scored higher on 8 of the tests despite costing about 50% less.
Opus 5’s edge was particularly pronounced across two benchmarks called Frontier-Bench and AutomationBench. The former test comprises 74 tasks spanning fields such as physics, chemistry and cryptography. Opus 5 performed 9.7% better than Fable 5. It achieved a 8.5% higher score on AutomationBench, which includes a set of knowledge work tasks.
