Claude Fable 5.1 Tops Artificial Analysis Intelligence Index Scoring 66

2 Sept 2026, 12:45 am · 11d ago · 1 min read · OfficeChai

Anthropic's Claude Fable 5.1 has captured the top position on the Artificial Analysis Intelligence Index, achieving an industry-leading score of 66. The performance marks a major leap for the AI model, surpassing Anthropic's Claude Opus 5 by three points to widen the company's benchmark lead. The Artificial Analysis Intelligence Index evaluates frontier large language models across multiple reasoning, coding, and problem-solving metrics. The milestone demonstrates Anthropic's sustained momentum in advancing model intelligence and competitive performance against rival frontier systems, offering developers and enterprises enhanced capabilities for complex reasoning and workflow automation.