GPT-5 Pro vs Grok 4 Fast
OpenAI vs xAI — benchmarks, pricing, and capabilities side by side.
- •GPT-5 Pro has the higher intelligence index (88.4 vs 78.7)
- •Grok 4 Fast is cheaper ($0.20 vs $15.00 per 1M input)
- •Grok 4 Fast has a larger context window (2M)
| GPT-5 Pro | Grok 4 Fast | |
|---|---|---|
| Intelligence index | 88.4 | 78.7 |
| Developer | OpenAI | xAI |
| Type | LLM | LLM |
| Access | API only | API only |
| Context window | 400,000 tokens | 2,000,000 tokens |
| Input price | $15.00 / 1M | $0.20 / 1M |
| Output price | $120.00 / 1M | $0.50 / 1M |
| Speed | — | 90 tok/s |
| Released | October 6, 2025 | September 19, 2025 |
| Parameters | — | — |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
Shared benchmarks
GPT-5 Pro
Grok 4 Fast
GPQA Diamond
88.4
85.7
Humanity’s Last Exam
42
20