[AINews] Claude Opus 5: Fable-level performance at Opus price (half Fable)

Latent Space · 2 months ago · 21 ● 17 sources

Anthropic released Claude Opus 5 on Friday, achieving an Epoch Capabilities Index score of 159 compared to Fable 5's 161, with matching software engineering performance at 161 SWE-ECI. Users reported strong practical performance on coding tasks and browser automation despite benchmark results appearing to understate improvements, while community debate focused on evaluation methodology and whether public benchmarks adequately capture real-world capabilities. The launch highlighted broader tensions between aggregate benchmark scores and specialized performance in domains like software engineering, and sparked discussion about test-time compute scaling and the need for harder public evaluation standards.