GPT-5.6 Terra and Grok‑1 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Grok‑1 shipped 966 days before GPT-5.6 Terra, so benchmark comparisons should account for the intervening progress.

GPT-5.6 Terra is proprietary, while Grok‑1 is open weight.

Direct benchmark comparisons are unavailable — GPT-5.6 Terra and Grok‑1 don't publish scores on any of the same benchmarks.