Anthropic's Claude and xAI's Grok, compared through their current models on the Respan Index. The strongest Claude model today is Claude Opus 5.5 (#1 on the Respan Index, 72.4); the strongest Grok model is Grok 4.6 (#19, 51.0). Claude's best models lead in coding, agents, reasoning, knowledge and human preference.
| Category | Claude | Grok |
|---|---|---|
| coding | Claude Opus 5.5 72.8 | Grok 4.7 43.2 |
| agents | Claude Sonnet 5.5 78.1 | Grok 4.7 65.6 |
| reasoning | Claude Opus 5.5 75.5 | Grok 4.6 51.7 |
| knowledge | Claude Fable 5 72.4 | Grok 4.7 55.7 |
| human preference | Claude Opus 5.5 60.6 | Grok 4.7 |
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 Claude model is Claude Haiku 4.5 at $2 per 1M tokens blended; the cheapest Grok model is Grok 4.1 Fast Reasoning at $0.275.