xAI builds the Grok line. Grok 4.6 (Aug 2026) prices above 4.5 with independent numbers still landing; both carry a context surcharge above 200K tokens that roughly doubles rates.
xAI, founded 2023, builds the Grok line and enters the flagship range with Grok 4.6 (August 2026), priced above Grok 4.5. It is the youngest lab holding a flagship-tier position in the survey.
That placement carries an explicit caveat. Grok 4.6's independent numbers had not landed as of the survey, so its flagship standing rests on vendor positioning rather than an Artificial Analysis index. Grok 4.5, by contrast, carries an independent mark of 54 — a balanced-tier standing that is verified where 4.6's is not. The register flags this rather than assuming the newer model inherits the older one's validated position.
Both Grok models apply a context surcharge above 200K tokens that roughly doubles the rate — a cost structure buyers should price in, and one several flat-rate competitors do not impose. The item to watch is straightforward: independent 4.6 numbers, which will confirm or revise its flagship placement.