This entry is a serving variant of OpenAI: GPT-5 Pro. A variant shares its base model's tokenizer by construction, so the measurement lives on the base record and this page inherits it.
| Signal | Result | Reference |
|---|---|---|
| Tokenizer signature | Not measured | – |
| API surface | Identical contract to 1 other entry | api_365b857b |
| Context and output | 400,000 context · 128,000 max output | declared |
| Reasoning contract | Mandatory · efforts high · default high | declared |
| Serving providers observed | None recorded yet | – |
GPT-5 Pro is OpenAI’s most advanced model, offering major improvements in reasoning, code quality, and user experience. It is optimized for complex tasks that require step-by-step reasoning, instruction following, and...
Supported parameters
include_reasoningmax_tokensreasoningreasoning_effortresponse_formatseedstructured_outputstool_choicetools
defaults: {"temperature":null,"top_p":null,"frequency_penalty":null}
Cite this page as the evidence record for OpenAI: GPT-5 Pro (batch): the URL is stable, measurements are dated, and revisions append to the history above. Method: tokenizer fingerprinting, v1, 50 strings. The raw data behind every figure is on the data page.
