OpenAI: GPT-5.5 vs xAI: Grok 4.5
OpenAI: GPT-5.5 wins on more metrics (5 of 9), but the right pick depends on what you optimize for — see the breakdown below.
| Metric | OpenAI: GPT-5.5 | xAI: Grok 4.5 |
|---|---|---|
| Intelligence Index | 54.8✓ | 53.8 |
| Coding Index | 74.9✓ | 72.4 |
| GPQA Diamond | 94%✓ | 93% |
| Design Arena Elo | 1301✓ | — |
| Speed (tokens/sec) | 50 | 74✓ |
| Latency | 3.0s | 655ms✓ |
| Input price /M | $5.00 | $2.00✓ |
| Output price /M | $30.00 | $6.00✓ |
| Context window | 1.1M✓ | 500K |
| Capabilities | ReasoningToolsJSONVision | ReasoningToolsJSONVision |