Comparisons › GPT-6 Astra vs Claude Fable 5.1: same price, same index

GPT-6 Astra vs Claude Fable 5.1: same price, same index

The two most capable models we track, priced identically and level on the intelligence index. This is the rare comparison where price genuinely does not decide it.

At a glance

Model compared

GPT-6 Astra	Claude Fable 5.1	Claude
Flagship model	GPT-6 Astra	Claude Fable 5.1
Input / 1M	$10	$10
Output / 1M	$50	$50
Intelligence index	53	53
Tokens / $1	25.0k	25.0k
Intelligence / $1	13,250	13,250
Cheapest plan	ChatGPT Plus ($20/mo)	Claude Pro ($20/mo)

Price

Identical: $10 per 1M input tokens and $50 per 1M output tokens. There is no promotional or off-peak discount on either, and neither offers a cheaper region or tier of the same model — so the only lever you have is how many tokens you send.

Capability

Both sit at the top of our intelligence index, and both are built for agentic, multi-step work rather than quick chat. Claude Fable 5.1 is the model practitioners call the one-shot king — it holds front-end design quality better across long generations — while GPT-6 Astra is OpenAI's new top tier and brings the wider OpenAI tooling ecosystem with it.

When to pick which

If design quality and getting it right on the first pass drive the outcome, pick Fable 5.1. If your work lives inside OpenAI's ecosystem — assistants, function calling, existing tooling — Astra is the natural choice. For high-volume work, both vendors sell much cheaper models that are close enough on most tasks: GPT-5.6 Sol at $4 / $20 and Claude Opus 5 at $5 / $25.

Bottom line: A genuine coin-flip on price and capability: pick Claude for design and one-shot quality, OpenAI for ecosystem and tooling. If you are cost-sensitive, both have far cheaper siblings that most workloads do not need to leave.