InferIndex · https://inferindex.dev/en/compare/anthropic/claude-fable-5.1/vs/openai/gpt-6-astra
Claude Fable 5.1 costs from $20.00 per million tokens and GPT-6 Astra from $20.00 (at a 3:1 input:output mix): the cheapest price for each; prices checked on .
Verdict
At these prices, the two models cost about the same per million tokens (at a 3:1 input:output mix).
Each model's lowest blended price, per 1M tokens, across every provider we track.
| Model | Lowest blended price, $ per 1M tokens. Green background: the most favourable value of each column. | Input price of the cheapest offer, per 1M tokens | Output price of the cheapest offer, per 1M tokens | The provider's published policy says the text you send is not used to train models. We only show what is published; we can't check it ourselves. | For 2,000 input tokens and 500 output tokens per request, 1,000 requests a day, at the cheapest offer for that workload. Change the workload above. | Offers | Providers | The maximum amount of text, counted in tokens, the model can take in and write in a single request. Past this limit, the request is refused or cut. | Observation |
|---|---|---|---|---|---|---|---|---|---|
| Most expensive offer · $22.00. The highest blended price among comparable offers: one price per provider (its cheapest route), standard tier, current prices only. Priority tiers and prices converted from points are not counted. | $10.00 | $50.00 | $20.00 | $1,350.00at Anthropic | 31 | 21 | 1M | ||
| Most expensive offer · $120.00. The highest blended price among comparable offers: one price per provider (its cheapest route), standard tier, current prices only. Priority tiers and prices converted from points are not counted. | $10.00 | $50.00 | $20.00 | $1,350.00at OpenAI | 45 | 21 | 1.1M |
Green background: the most favourable value of each column.
Prices as of Oct 31, 2026, 8:04 AM UTCSame rules as the API's /cheapest route. The monthly estimate uses the cheapest offer for that workload.
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