Google: Gemini 3.5 Flash wins on more metrics (8 of 9), but the right pick depends on what you optimize for — see the breakdown below.
| Metric | Google: Gemini 3.5 Flash | OpenAI: GPT-5.3-Codex |
|---|---|---|
| Intelligence Index | 54.8✓ | 53.6 |
| Coding Index | 43.9 | 53.1✓ |
| GPQA Diamond | 92%✓ | 92% |
| Design Arena Elo | 1329✓ | 1230 |
| Speed (tokens/sec) | 174✓ | 45 |
| Latency | 1.9s✓ | 4.4s |
| Input price /M | $1.50✓ | $1.75 |
| Output price /M | $9.00✓ | $14.00 |
| Context window | 1.0M✓ | 400K |
| Capabilities | ReasoningToolsJSONVisionAudio | ReasoningToolsJSONVision |