Claude Opus 4.8 vs Grok-4 Heavy
Anthropic vs xAI — benchmarks, pricing, and capabilities side by side.
- •Grok-4 Heavy has the higher intelligence index (78.5 vs 73.1)
| Claude Opus 4.8 | Grok-4 Heavy | |
|---|---|---|
| Intelligence index | 73.1 | 78.5 |
| Developer | Anthropic | xAI |
| Type | LLM | Multimodal |
| Access | — | API only |
| Context window | — | — |
| Input price | $6.30 / 1M | — |
| Output price | $25.00 / 1M | — |
| Speed | 66 tok/s | — |
| Released | May 28, 2026 | July 9, 2025 |
| Parameters | — | — |
| Input modalities | — | — |
| Output modalities | — | — |
Shared benchmarks
Claude Opus 4.8
Grok-4 Heavy
GPQA Diamond
92
88.4
Humanity’s Last Exam
45.7
50.7