Claude Fable 5 leads HLE (Humanity's Last Exam) in 2026 at 53.3%. Claude Opus 5 Max leads Intelligence Index at 60.7 (Xhigh 60.1, Fable 5 59.9). GPT-5.6 Sol max (HLE 47.2%, GPQA 94.1% co-leader), Claude Opus 4.8 (HLE 45.7%) compared. Ranked by GPQA Diamond, AIME, MATH-500, HLE. Free.
| # | Model | Score | Benchmarks | Input $/M | Output $/M | Speed | TTFT |
|---|
Models are scored using a weighted combination of benchmarks, pricing, and speed metrics relevant to this use case.
Models specifically designed for reasoning (like OpenAI o-series and DeepSeek R1) typically score highest on benchmarks like GPQA, AIME, and HLE. Check the rankings above for the latest results.
For tasks requiring genuine multi-step logic — math proofs, complex analysis, scientific research — yes. For simpler tasks, general-purpose models are more cost-effective.
Chain-of-thought (CoT) is when a model shows its step-by-step thinking process. Some models do this internally (hidden tokens), while others expose it. CoT generally improves accuracy on complex problems but increases token usage.