GPT-5.5
FrontierClosed weightsTextReasoning
GPT-5.5 family model by OpenAI.
About the GPT-5.5 family
OpenAI's early-2026 frontier model, available from non-reasoning up to xhigh effort settings.
All GPT-5.5 modelsHow this one is configured
This configuration runs in reasoning mode (thinks step-by-step before answering).
Also runs at: low · medium · high · xhigh effort
Effort controls how long the model thinks before answering — higher effort usually means better answers on hard problems, at the cost of speed and money. Same model underneath, so they share this page.