Claude Opus 5 leads on agentic work — and undercuts Fable 5 on cost

Claude Opus 5, Anthropic's new model, leads on agentic knowledge work and undercuts Fable 5 on cost, according to Artificial Analysis. The model scores 61 on the Artificial Analysis Intelligence Index, effectively tied with Fable 5's 60, but offers better agentic outcomes at a lower price. However, its hallucination rate climbed to 50%, making Fable 5 preferable for factual precision tasks.

Claude Opus 5 is out, and Artificial Analysis — who supported Anthropic's pre-release evaluation — just dropped their full benchmark breakdown. The headline: new top model for agentic knowledge work, and cheaper per task than Fable 5. That combination doesn't come along often at the frontier. "Opus 5 max scores 61 on the Artificial Analysis Intelligence Index, effectively tied with Claude Fable 5 max, 60 , and ahead of GPT-5.6 Sol max, 59 " For agentic workloads — the things most teams are actually building on right now — Opus 5 doesn't just match Fable 5. It beats it, and charges less to do it. Fable 5 was the "throw more at it" option. Opus 5 reframes the trade-off: better agentic outcomes and a lower bill. At mid-tier effort settings high, xhigh , it can outperform both Opus 4.8 and Sonnet 5 on a cost-per-task basis. That's a lot of headroom to play with before you're even at max effort. The caveat worth flagging: factual knowledge still lags. Opus 5 improved +7 points on AA-Omniscience over Opus 4.8, but its hallucination rate climbed 14 points to 50% — it guesses more confidently when uncertain. For retrieval-heavy or factual precision tasks, Fable 5 still holds the edge. high or xhigh effort before committing to max .Full benchmark breakdown: Artificial Analysis — Claude Opus 5 https://artificialanalysis.ai/articles/opus-5 ✏️ Drafted with KewBot AI , edited and approved by Drew.