GPT-5.5 vs Grok 4.20 0309 v2
OpenAI vs xAI — benchmarks, pricing, and capabilities side by side.
- •Grok 4.20 0309 v2 has the higher intelligence index (91.1 vs 76.1)
- •Grok 4.20 0309 v2 is cheaper ($2.00 vs $5.00 per 1M input)
- •Grok 4.20 0309 v2 is faster
| GPT-5.5 | Grok 4.20 0309 v2 | |
|---|---|---|
| Intelligence index | 76.1 | 91.1 |
| Developer | OpenAI | xAI |
| Type | LLM | LLM |
| Access | API only | — |
| Context window | 1,050,000 tokens | — |
| Input price | $5.00 / 1M | $2.00 / 1M |
| Output price | $30.00 / 1M | $6.00 / 1M |
| Speed | 67 tok/s | 105 tok/s |
| Released | April 23, 2026 | April 7, 2026 |
| Parameters | — | — |
| Input modalities | Text, Image | — |
| Output modalities | Text | — |
Shared benchmarks
GPT-5.5
Grok 4.20 0309 v2
GPQA Diamond
93.5
91.1
Humanity’s Last Exam
44.3
32.2