Artificial intelligence · July 2026

Claude Opus 5

Near-Fable capability at half the price.

Claude Opus 5 came close to Fable 5 at half its price and set new state-of-the-art results on Frontier-Bench and GDPval-AA. Its ARC-AGI-3 score was three times the next-best model's.

See it in the living tree Wikipedia Source

Arcs above join it to what it stood on, arcs below to what it led to. The bar places this stretch on the tree's whole timeline.

What it built on 1

Claude Fable 5 and Mythos 5 2026

What it led to 3

Two thirds of zeta zeros on the line 2026
Fermat's Last Theorem machine-checked 2026
Claude Opus 5.5 2026

Related measurements

The dashed line marks when it first worked.

Best AI score on GPQA Diamond Latest: 95.8 % correct (2026) Source: Epoch AI, Capabilities & benchmarking (benchmark_data.zip, gpqa_diamond.csv); Anthropic: Claude 3 public launch (March 4, 2024)

Training compute of notable AI models Source: Epoch AI, Notable AI Models (CC BY 4.0)