GPT-5.1 vs Grok-1.5
OpenAI vs xAI — benchmarks, pricing, and capabilities side by side.
- •GPT-5.1 has the higher intelligence index (89 vs 50.3)
| GPT-5.1 | Grok-1.5 | |
|---|---|---|
| Intelligence index | 89 | 50.3 |
| Developer | OpenAI | xAI |
| Type | LLM | LLM |
| Access | API only | API only |
| Context window | 400,000 tokens | — |
| Input price | $1.25 / 1M | — |
| Output price | $10.00 / 1M | — |
| Speed | 115 tok/s | — |
| Released | November 12, 2025 | March 28, 2024 |
| Parameters | — | — |
| Input modalities | Text, Image | — |
| Output modalities | Text | — |
Shared benchmarks
GPT-5.1
Grok-1.5
GPQA Diamond
88.1
35.9
MMLU-Pro
87
51