GPT-5.5-PRO
GPT-5.5-PRO is a chat model developed by OpenAI, capable of handling a wide range of tasks including text generation, reasoning, and function calling. It is genuinely best at tasks that require extensive context understanding, thanks to its large context window of 1,050,000 tokens.
Input
Output
Context
1050K
Max Output
128K
Parameters
-
Technical Specifications
Model TypeChat
Context Window1,050,000 tokens
Max Output Tokens128,000 tokens
ParametersNot available
Release DateApr 22, 2026
Training CutoffDec 1, 2025
Licenseproprietary
Open SourceNo
Input Modalities
ImageText
Output Modalities
Text
Capabilities
Resources & Links
proprietary, Proprietary - API access only
More Models by OpenAI
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Data sourced from official provider APIs and documentation
Last updated: Aug 8, 2026
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