ImprovementModels ·
GPT-5.5
Try in the builder
Create an agent or open an existing agent in the builder, then follow the steps below. Model and feature availability may depend on your plan.
What it does
OpenAI's GPT-5.5 became available across the builder.
Before this
An addition to the selector. GPT-5.4 and its Pro, mini, and nano variants were already available; 5.5 replaces 5.4 as the general-purpose default.
Why it matters
The general-purpose default for agents where you'd rather not think about model choice at all.
The specs
- Context
- 1,050,000 tokens in, up to 128,000 out.
- Input
- Text and images.
- Actions
- Supported.
- Reasoning
- Fast ($$), Smart ($$$), or Smartest ($$$$).
- Plans
- Gold and Pro.
Tagged 'smartest' in the selector, and the sane default for an agent where you would rather not think about model choice at all — good enough at everything that the choice stops being the thing limiting your agent.