Anthropic: Claude Opus 4.6 and OpenAI: GPT-5.5 are evenly matched; the right pick depends on your priorities.
| Metric | Anthropic: Claude Opus 4.6 | OpenAI: GPT-5.5 |
|---|---|---|
| Intelligence Index | 52.9 | 56.7✓ |
| Coding Index | 48.1 | 56.2✓ |
| GPQA Diamond | 90% | 93%✓ |
| Design Arena Elo | 1358✓ | 1354 |
| Speed (tokens/sec) | 45✓ | 29 |
| Latency | 1.6s✓ | 2.8s |
| Input price /M | $5.00 | $5.00 |
| Output price /M | $25.00✓ | $30.00 |
| Context window | 1M | 1.1M✓ |
| Capabilities | ReasoningToolsJSONVision | ReasoningToolsJSONVision |