Humanity's Last Exam

Comprehensive benchmark designed to evaluate AI models across broad knowledge domains and reasoning capabilities. claude-fable 5 achieved 53% performance, more than 7 points ahead of the next-best model.

Performance Results

Strong performance with clear competitive advantage:

• claude-fable 5: 53%
• Next-best model: <46%
• Performance gap: 7+ points

Fallback Routing Behavior

Humanity's Last Exam provides insight into claude-fable's fallback-routing system:

• Fallback frequency: 9% of HLE tasks triggered fallback to claude-opus-48
• Safety triggers: Likely related to cyber/bio/chemistry content
• Transparent routing: Users notified when fallback occurs

Benchmark Characteristics

The name "Humanity's Last Exam" suggests:

• Comprehensive evaluation across human knowledge domains
• High-stakes assessment methodology
• Potentially philosophical or existential framing
• Broad coverage beyond narrow technical skills

Role in Intelligence Assessment

Part of broader intelligence evaluation alongside:

• Intelligence Index: 64.9 (#1 performance)
• GDPval-AA Elo: 1932 (agentic knowledge work)
• AA-Omniscience: Knowledge benchmark improvements

Safety Architecture Insights

The 9% fallback rate on HLE tasks provides data on safety system activation patterns, showing that sensitive content detection occurs even in general knowledge evaluation contexts.

See also

• benchmark-leadership
• claude-fable
• fallback-routing
• intelligence-assessment
• knowledge-evaluation