Anthropic: Claude Fable 5 vs OpenAI: GPT-5.6 Luna
OpenAI: GPT-5.6 Luna wins on more metrics (5 of 9), but the right pick depends on what you optimize for — see the breakdown below.
| Metric | Anthropic: Claude Fable 5 | OpenAI: GPT-5.6 Luna |
|---|---|---|
| Intelligence Index | 59.9✓ | 51.2 |
| Coding Index | 76.5✓ | 71.4 |
| GPQA Diamond | 93%✓ | 91% |
| Design Arena Elo | 1379✓ | — |
| Speed (tokens/sec) | 38 | 60✓ |
| Latency | 6.4s | 1.7s✓ |
| Input price /M | $10.00 | $1.00✓ |
| Output price /M | $50.00 | $6.00✓ |
| Context window | 1M | 1.1M✓ |
| Capabilities | ReasoningToolsJSONVision | ReasoningToolsJSONVision |