Claude Fable 5.1 vs GPT-6 Astra.
Claude Fable 5.1 is 1.0x cheaper.

For a chatbot doing 100K requests a month with 1,000 input and 500 output tokens each: $3,500.00 vs $3,500.00.

Anthropic

Claude Fable 5.1

Input / 1M$10.00
Cached / 1M$0.25
Output / 1M$50.00
Context—
Chatbot at 100K req/mo$3,500.00

Source · Oct 20, 2026

OpenAI

GPT-6 Astra

Input / 1M$10.00
Cached / 1M$1.00
Output / 1M$50.00
Context—
Chatbot at 100K req/mo$3,500.00

Source · Oct 20, 2026

Price isn't everything: check quality on your own prompts. Claude Fable 5.1 wins on list price for this workload, but output-heavy jobs (long answers, agents, reasoning) shift the math toward whichever model has the lower output price. Here both charge the same for output.

Run your own workload