XA
xAI / SpaceXAI (Elon Musk)
Developer and publisher of Grok 4.6; Musk publicly framed the release as leapfrogging rivals on cost-efficiency and signaled an aggressive iteration cadence toward Grok 4.7.
Primary benchmark rival; GPT-5.6 Sol ties Grok 4.6 on the Artificial Analysis Intelligence Index but costs significantly more per token and offers a larger 1M-token context window.
AN
Anthropic (Claude Opus 5 / Claude Fable 5)
Higher-scoring rivals on the Intelligence Index and top-ranked on the GDPval-AA v2 agentic benchmark, but at much higher per-token cost than Grok 4.6.
Coding tool that shipped Grok 4.6 immediately on all plans with promotional double usage for the first week.
Agentic coding platform that integrated Grok 4.6 into Devin Desktop and CLI, highlighting its code-exploration and root-cause-analysis strength.
Independent benchmarking organization that published the headline Intelligence Index comparison placing Grok 4.6 at 61, tied with GPT-5.6 Sol.