GPT-5.5 Pro

GPT-5.5 Pro lists base rates of $30 per million input tokens and $180 per million output tokens. Estimate both input and output token volume and any additional charges for your workload. All amounts are USD per MTok; long-context bands apply to the full request, not just excess tokens. Standard <=272K input: input/output $30.00/$180.00, cached input not quoted, 30-minute write not quoted, 12-hour write not quoted; >272K: input/output $60.00/$270.00, cached input not quoted, 30-minute write not quoted, 12-hour write not quoted. Batch <=272K input: input/output $15.00/$90.00, cached input not quoted, 30-minute write not quoted, 12-hour write not quoted; >272K: input/output not quoted/not quoted, cached input not quoted, 30-minute write not quoted, 12-hour write not quoted. Flex <=272K input: input/output $15.00/$90.00, cached input not quoted, 30-minute write not quoted, 12-hour write not quoted; >272K: input/output not quoted/not quoted, cached input not quoted, 30-minute write not quoted, 12-hour write not quoted. Regional processing and FedRAMP add 10% where the model and route are eligible; region eligibility is separate from a quoted tariff. Server-side tools and their tokens can add charges. No cached-input discount. Responses, including Batch, is supported; streaming is not. The current Batch/Flex long-context price cells are unquoted, so confirm those terms rather than inferring a discount.

GPT-5.5 Pro accepts about 1.05M tokens of context. That only matters if you routinely send very long documents, large codebases, or multi-turn histories that approach that limit.

GPT-5.5 Pro is a frontier tier from OpenAI. It suits maximum-accuracy reasoning, research, hard enterprise workloads. Requests may take several minutes; OpenAI recommends background mode to avoid timeouts. The API model card lists no streaming. Evaluate the $30/$180 rate on your workload rather than assume this is OpenAI’s globally most expensive or most accurate model.