Side-by-side comparison of pricing, 12 benchmarks, and generation speed.
| Metric | Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback) | GPT-5.5 (low) |
|---|---|---|
| Input ($/M tokens) | $10 | $5 |
| Output ($/M tokens) | $50 | $30 |
Data from Artificial Analysis API — 12 benchmarks
GPT-5.5 (low) is cheaper overall. Its blended price (3:1 input/output ratio) is $11.25/M tokens vs $20.00/M for Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback).
Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback) wins 6 out of 12 benchmarks compared to 1 for GPT-5.5 (low). See the detailed benchmark chart above for per-category results.
Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback) generates tokens faster at 68 tok/s vs 67 tok/s. However, GPT-5.5 (low) has lower time-to-first-token (1.63s vs 46.22s).
Choose based on your priorities: GPT-5.5 (low) for lower cost, Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback) for stronger benchmark performance, and Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback) for faster generation. For latency-sensitive apps, check the TTFT comparison above.