Chat-tuned GPT-5.1 for polished assistants, writing, and product conversations
GPT-5.1 Chat by openai is offered by 6 providers on this page. Its reference price is $1.25 per 1M input tokens and $10.00 per 1M output tokens.
The context window is 128,000 tokens at the reference host, but hosts report different limits, from 128,000 to 400,000, so the usable window depends on the provider you pick. It supports reasoning, tool use, and structured output. Accepted input modalities are Text, Image, and PDF. Providers report the capability flags inconsistently, so verify a specific feature against the host you plan to use. Its training knowledge cuts off at 2024-09-30.
| Provider | Tier | Input | Output | Cache read | Cache write | Context | Output limit | Status |
|---|---|---|---|---|---|---|---|---|
| OrcaRouter | Gateway | $1.25 | $10.00 | $0.125 | — | 128,000 | 16,384 | |
| ZenMux openai/gpt-5.1-chat | Gateway | $1.25 | $10.00 | $0.12 | — | 128,000 | 64,000 | |
| Merge Gateway | Gateway | $1.25 | $10.00 | $0.125 | — | 128,000 | 16,384 | |
| Abacus | Gateway | $1.25 | $10.00 | — | — | 400,000 ⚠ | 128,000 | |
| 302.AI | Gateway | $1.25 | $10.00 | — | — | 128,000 | 16,384 | |
| Helicone | Gateway | $1.25 | $10.00 | $0.125 | — | 128,000 | 16,384 |
Sorted by blended price (input×0.75 + output×0.25) asc. The official channel always shows regardless of rank. Whether a gateway's low price is actually usable can't be verified.
2 / 6 providers expose no reasoning control (reasoning_options: []).