GPT-6 Astra vs Claude Fable 5.1: API cost
Standard, cached and batch API prices for GPT-6 Astra (OpenAI) and Claude Fable 5.1 (Anthropic), and what each costs for your usage.
GPT-6 Astra and Claude Fable 5.1 have the same standard input and output prices, but Claude Fable 5.1’s cached input is 4× cheaper, so it costs less when part of your prompt is cached.
- Input $300.00
- Cached input $30.00
- Output $450.00
- Input $300.00
- Cached input $7.50
- Output $450.00
| Token type | GPT-6 Astra | Claude Fable 5.1 | |
|---|---|---|---|
| Input | $10 | $10 | Same price |
| Cached input | $1 | $0.25 | Claude Fable 5.1 is 4× cheaper |
| Output | $50 | $50 | Same price |
| Batch input | $5 | $5 | Same price |
| Batch cached input | $0.50 | $0.125 | Claude Fable 5.1 is 4× cheaper |
| Batch output | $25 | $25 | Same price |
GPT-6 Astra: Long prompts are billed at higher long-context rates.
| Workload | GPT-6 Astra | Claude Fable 5.1 |
|---|---|---|
Support chatbot 2,000 in / 300 out tokens,
1,000 requests a day, 50% cached | $780.00 | $757.50 |
Document summaries 10,000 in / 800 out tokens,
200 requests a day | $840.00 | $840.00 |
Tagging / classifying 400 in / 20 out tokens,
20,000 requests a day | $3,000 | $3,000 |
More comparisons
- GPT-6 Astra vs GPT-6 Sol
- GPT-6 Astra vs Gemini 3.1 Pro Preview
- Claude Fable 5.1 vs Claude Opus 5.5
- Claude Fable 5.1 vs Gemini 3.1 Pro Preview
Or see GPT-6 Astra pricing, Claude Fable 5.1 pricing, or compare any two models.
FAQ
Frequently asked questions
Is GPT-6 Astra cheaper than Claude Fable 5.1?
GPT-6 Astra and Claude Fable 5.1 have the same standard input and output prices, but Claude Fable 5.1’s cached input is 4× cheaper, so it costs less when part of your prompt is cached. Based on standard API rates last checked on 30 Sept 2026.
How much do GPT-6 Astra and Claude Fable 5.1 cost per million tokens?
GPT-6 Astra: $10 per million input tokens and $50 per million output tokens. Claude Fable 5.1: $10 input and $50 output. These are standard rates in USD, before tax, from each provider’s own pricing page.
Which is cheaper with the Batch API?
GPT-6 Astra’s batch rates are $5 input and $25 output per million tokens (50% off); Claude Fable 5.1’s batch rates are $5 input and $25 output per million tokens (50% off).
Does prompt caching change the comparison?
GPT-6 Astra charges $1 per million cached input tokens, against $10 for normal input; Claude Fable 5.1 charges $0.25 per million cached input tokens, against $10 for normal input. Cache write and storage charges are extra and aren’t included here.