GPT 5.1 Thinking (Fast): API pricing, providers and specs
GPT 5.1 Thinking (Fast) is a text model by OpenAI. One provider serves it: Vercel AI Gateway, at $20 /1M.
How GPT 5.1 Thinking (Fast) compares
Against the 737 text models on the site priced the same way.
- Pricey for its class: at $20 /1M, its lowest price is above 93% of comparable models (median $1.10).
- Its 400K-token context window is larger than 62% of them (median 262K), about 600 pages of text.
- 1 providers serve it; 0% of comparable models have fewer.
GPT 5.1 Thinking (Fast) prices by provider
Every provider's list price, read from its own price page or API. A price marked “from” changes with context length, resolution or mode.
| Provider | Input | Output | Prompt caching | Context |
|---|---|---|---|---|
| Vercel AI Gateway | $2.50/1M | $20/1M | $0.25/1M | 400K |
Specs
- Type
- Text
- Maker
- OpenAI
- Inputs
- Image, Text
- Outputs
- Text
- Context
- 400K≈ 600 pages of text
- Max output
- 128K
- Capabilities
- Prompt caching, JSON, Reasoning, Tool calling, Vision
- Released
- Nov 12, 2025
- License
- —
- Open weights
- —
Alternatives to GPT 5.1 Thinking (Fast)
Same kind of model from other makers, at a similar price.
| Model | Lowest price | Context | Arena | Providers |
|---|---|---|---|---|
| GPT 5.1 Thinking (Fast)this model | $20/1M | 400K | — | 1 |
 Gemini 4 Argon | $8/1M | 1.05M | 1673 | 26 |
| Kimi K3 | $8.28/1M | 1.05M | 1655 | 47 |
 Muse Wonder | $16/1M | 1.05M | — | 14 |
| Claude Opus 5.5 | $16/1M | 1M | 1807 | 33 |
| Claude Sonnet 5.5 | $8/1M | 1M | 1767 | 32 |
| Claude-Sonnet-3.5 | $15/1M | — | 1298 | 1 |
| Claude Opus 5 | $20/1M | 1M | 1690 | 32 |
| Claude Sonnet 4.6 | $12/1M | 1M | 1523 | 31 |
More from OpenAI
GPT 5.1 Thinking (Fast) FAQ
The lowest price for GPT 5.1 Thinking (Fast) is $20 /1M, at Vercel AI Gateway.
GPT 5.1 Thinking (Fast) reads up to 400K tokens per request and writes up to 128K.
We have not found GPT 5.1 Thinking (Fast)'s weights published by its maker.
1 API providers serve GPT 5.1 Thinking (Fast). Compare their prices above, or open a provider to see everything it offers.
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