GPT-5.5 Pro
OpenAI
openai/gpt-5.5-proGPT-5.5 Pro is the extended-reasoning tier of GPT-5.5, for the hardest coding, research, and analytical tasks where maximum accuracy is worth the extra latency and cost.
Cost rate
35x
Context
1.1M
Released
Apr 24, 2026
Input
FileImageText
Output
Text
Support
ReasoningTool callingStructured outputs