GPT-5.5 Pro
GPT-5.5 Pro spends more computation on difficult reasoning tasks. It supports Responses requests, including Batch, and can take several minutes to complete a request.
Long-running work needs a suitable request lifecycle
The model supports medium, high and xhigh reasoning, with high as the default. OpenAI recommends background mode to avoid timeouts on demanding requests. Its input pricing has no cache discount, unlike the standard GPT-5.5 model.GPT-5.5 Pro official model documentation
Compare the value of deeper reasoning
Practical guidance. Use a difficult task with a clear review standard, such as a technical argument with evidence. Keep the request state visible while work continues. A more expensive answer should be judged by whether it resolves the hard part of the task.
Specifications & access
| Detail | Value and conditions |
|---|---|
| Access | API |
| Model identifiers | gpt-5.5-progpt-5.5-pro-2026-04-23 |
| Context window | 1,050,000 tokens Published model context; input and output share this budget GPT-5.5 Pro official model documentation |
| Maximum output | 128,000 tokens Published maximum output; bounded by the remaining context GPT-5.5 Pro official model documentation |
| Input price | 30 USD per million tokens Standard text processing at the reviewed date GPT-5.5 Pro official model documentation |
| Output price | 180 USD per million tokens Standard text processing at the reviewed date GPT-5.5 Pro official model documentation |
| Input and output | text, image in; text outGPT-5.5 Pro official model documentation |
| API routes | Responses (v1/responses); Batch (v1/batch)GPT-5.5 Pro official model documentation |
Related models
GPT-5.5 supports demanding coding and professional tasks through text and image input.
Launch date not confirmedAPI