Google: Gemini 3.1 Pro Preview wins on more metrics (7 of 9), but the right pick depends on what you optimize for — see the breakdown below.
| Metric | Google: Gemini 3.1 Pro Preview | OpenAI: GPT-5.2-Codex |
|---|---|---|
| Intelligence Index | 46.5✓ | 40.1 |
| Coding Index | 68.8✓ | — |
| GPQA Diamond | 94%✓ | 90% |
| Design Arena Elo | 1347✓ | — |
| Speed (tokens/sec) | 103✓ | 64 |
| Latency | 2.8s | 1.6s✓ |
| Input price /M | $2.00 | $1.75✓ |
| Output price /M | $12.00✓ | $14.00 |
| Context window | 1.0M✓ | 400K |
| Capabilities | ReasoningToolsJSONVisionAudio | ReasoningToolsJSONVision |