OpenAI: GPT-5.3-Codex wins on more metrics (6 of 9), but the right pick depends on what you optimize for — see the breakdown below.
| Metric | Anthropic: Claude Opus 4.6 | OpenAI: GPT-5.3-Codex |
|---|---|---|
| Intelligence Index | 52.9 | 53.6✓ |
| Coding Index | 48.1 | 53.1✓ |
| GPQA Diamond | 90% | 92%✓ |
| Design Arena Elo | 1358✓ | 1229 |
| Speed (tokens/sec) | 42 | 50✓ |
| Latency | 1.7s✓ | 3.5s |
| Input price /M | $5.00 | $1.75✓ |
| Output price /M | $25.00 | $14.00✓ |
| Context window | 1M✓ | 400K |
| Capabilities | ReasoningToolsJSONVision | ReasoningToolsJSONVision |