GPT-6 Astra vs Claude Fable 5.1: Which Is Better?

GPT-6 Astra vs Claude Fable 5.1: Which Is Better?

Two models, one price tag: $10 per million input tokens, $50 per million output tokens. GPT-6 Astra shipped on September 3, Claude Fable 5.1 on September 1. Identical sticker prices, so the comparison looks simple. It is not. The sticker is the same, the bill is not. Run the same work through both and what you pay can double or halve depending on the shape of your workload. This post starts with where that gap comes from, then walks the benchmark table, and finishes with three concrete billing scenarios. ...

September 9, 2026 ·  10 min ·  2087 words