| Claude Fable 5 | GPT-5.5 | |
|---|---|---|
| arenaElo | 1492 | 1432 |
| humanEval | 98 | 94.2 |
| sweBench | 77 | 66 |
| mmlu | 95.1 | 93 |
| gpqa | 92 | 68.7 |
| aime | 94 | 92 |
| Price in/out ($/M) | $10 / $50 | $12 / $48 |
Fable 5 leads on long-horizon autonomous agents, frontier reasoning and coding, and now ships generally available. GPT-5.5 keeps the multimodal edge (native audio and video) that Fable 5 does not match, plus a more mature tool-calling ecosystem. For agentic coding and research, Fable 5; for voice-first multimodal products, GPT-5.5. Benchmark both on your real workload before committing.