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Research · Aug 16, 2026, 03:05 AM · 4 sources

Grok 4.6 debuts at 61 AI Index score; 50% turn-efficient vs Claude Opus 5

xAI released Grok 4.6 on August 12, 2026, scoring 61 on the Artificial Analysis Intelligence Index, a +5 jump from Grok 4.5 and placing it level with GPT-5.6 Sol while remaining just behind Claude Opus 5 (63) and Claude Fable 5 (62). The model ships on the same $2/$6 per million token API pricing as Grok 4.5—about 60% cheaper than Claude Opus 5 ($5/$25) and GPT-5.6 Sol ($5/$30)—but the headline understates the real advantage.

Turn efficiency is the story: Artificial Analysis measured Grok 4.6 solving complex multi-step knowledge-work tasks in roughly 53 turns and 0.5 billion input tokens on average, while Claude Opus 5 needed approximately 103 turns and 2.0 billion tokens for the same work. This 50% reduction in turn count compounds over high-volume agentic workloads. Artificial Analysis calculated Grok 4.6 at $0.84 per completed task—identical to Kimi K3 but with higher measured intelligence—placing it on the Pareto frontier for cost-to-capability ratio. Context window remains 500K (versus Claude's 1M), and long-context pricing doubles above 200K tokens.

For teams evaluating multi-model routing strategies in 2026, Grok 4.6's economics force a recalculation: Claude Opus 5 remains the default for correctness-critical work, but Grok 4.6's turn efficiency makes it attractive for background agents, high-volume agentic tasks, and reasoning loops where Claude's latency and per-token cost would be prohibitive. The practical implication is that production stacks increasingly run Claude for critical paths and Grok for high-throughput subagents, a divergence that was cost-prohibitive a month ago.

Sources

Everything this brief rests on
  1. 01 Primary source codersera.com
  2. 02 codersera.com codersera.com “Grok 4.6 scored 61 on the Artificial Analysis Intelligence Index, a composite of nine benchmarks. That's five points above Grok 4.5”
  3. 03 how2shout.com how2shout.com “Artificial Analysis measured Grok 4.6 completing knowledge-work tasks in roughly 53 turns using about 0.5 billion input tokens. Claude Opus 5 needed around 103 turns and 2 billion tokens for the same work”
  4. 04 artificialanalysis.ai artificialanalysis.ai “Grok 4.6 calculated $0.84 per task, the same as Kimi K3 with slightly higher intelligence, placing it on the Intelligence vs. Cost per Task Pareto frontier”