OpenAI's GPT and xAI's Grok, compared through their current models on the Respan Index. The strongest GPT model today is GPT-6 Astra (#2 on the Respan Index, 70.5); the strongest Grok model is Grok 4.6 (#19, 51.0). GPT's best models lead in coding, agents, reasoning, knowledge and human preference.
| Category | GPT | Grok |
|---|---|---|
| coding | GPT-6 Astra 61.8 | Grok 4.7 43.2 |
| agents | GPT-6 Astra 77.0 | Grok 4.7 65.6 |
| reasoning | GPT-6.1 Sol 78.6 | Grok 4.6 51.7 |
| knowledge | GPT-6 Astra 75.8 | Grok 4.7 55.7 |
| human preference | GPT-6 Astra 59.7 | Grok 4.7 56.0 |
Each family's highest Respan Index category score; the higher one is bold. * Estimated: no published scores in that category. How the Respan Index works
Respan Index rank and score, blended list price per 1M tokens.
The cheapest ranked GPT model is GPT-5 nano at $0.138 per 1M tokens blended; the cheapest Grok model is Grok 4.1 Fast Reasoning at $0.275.