Google: Gemini 3.5 Flash wins on more metrics (6 of 9), but the right pick depends on what you optimize for — see the breakdown below.
| Metric | Google: Gemini 3.5 Flash | OpenAI: GPT-5 Codex |
|---|---|---|
| Intelligence Index | 43.3 | 44.6✓ |
| Coding Index | 47.1✓ | 38.9 |
| GPQA Diamond | 83% | 84%✓ |
| Design Arena Elo | 1328✓ | 1140 |
| Speed (tokens/sec) | 166✓ | 74 |
| Latency | 1.7s✓ | 2.8s |
| Input price /M | $1.50 | $1.25✓ |
| Output price /M | $9.00✓ | $10.00 |
| Context window | 1.0M✓ | 400K |
| Capabilities | ReasoningToolsJSONVisionAudio | ReasoningToolsJSONVision |