Anthropic: Claude Sonnet 5 wins on more metrics (7 of 9), but the right pick depends on what you optimize for — see the breakdown below.
| Metric | Anthropic: Claude Sonnet 5 | OpenAI: GPT-5.2-Codex |
|---|---|---|
| Intelligence Index | 53.4✓ | 40.1 |
| Coding Index | 71.5✓ | — |
| GPQA Diamond | 91%✓ | 90% |
| Design Arena Elo | 1330✓ | — |
| Speed (tokens/sec) | 73✓ | 64 |
| Latency | 2.5s | 1.6s✓ |
| Input price /M | $2.00 | $1.75✓ |
| Output price /M | $10.00✓ | $14.00 |
| Context window | 1M✓ | 400K |
| Capabilities | ReasoningToolsJSONVision | ReasoningToolsJSONVision |