GPT-5.5 Pro

Health in ChatGPT is starting to roll out to U.S. users. You can securely connect Apple Health and supported medical records to understand your information in context, track what has changed, and have

Health in ChatGPT is starting to roll out to U.S. users. You can securely connect Apple Health and supported medical records to understand your information in context, track what has changed, and have more informed conversations. https://t.co/W2E6oT8c91

Launching Health in ChatGPT

Introducing OpenAI Presence

We're partnering with @huggingface to investigate an unprecedented security incident. Cyber-capable OpenAI models compromised Hugging Face production during a benchmark evaluation. Sharing preliminary

We're partnering with @huggingface to investigate an unprecedented security incident. Cyber-capable OpenAI models compromised Hugging Face production during a benchmark evaluation. Sharing preliminary findings to help defenders understand emerging risks:

We’re sharing new research with @apolloaievals on reward-seeking—when models follow what they believe a grader rewards rather than what users or developers want—and a new method, Contrastive SDF, for

We’re sharing new research with @apolloaievals on reward-seeking—when models follow what they believe a grader rewards rather than what users or developers want—and a new method, Contrastive SDF, for measuring how strongly such beliefs shape behavior. https://t.co/z1oZXP7ntj

Introducing the ChatGPT for small business program

OpenAI and Hugging Face partner to address security incident during model evaluation

Safety and alignment in an era of long-horizon models

Update: GPT-5.5 and GPT-5.5 Pro are now available in the API.

Introducing GPT-5.2

Introducing GPT-5.2 | OpenAI Skip to main content Research Products Business Developers Company Foundation (opens in a new window) Log in Try ChatGPT (opens in a new window) Research Products Business Developers Company Foundation (opens in a new window) Try ChatGPT (opens in a new window) Login OpenAI December 11, 2025 Product Release Introducing GPT‑5.2 The most advanced frontier model for professional work and long-running agents. Loading… Share Model performance Model per

GPT-5.5 Pro Model | OpenAI API

GPT-5.5 Pro Model | OpenAI API ChatGPT Home API Codex Docs Guides, concepts, and product docs for Codex Use cases Example workflows and tasks teams can take on with ChatGPT or Codex Docs Use cases Resources ChatGPT Apps SDK Build apps to extend ChatGPT Workspace Agents Trigger published ChatGPT workspace agents Commerce Build commerce flows in ChatGPT Ads Publish and measure ads in ChatGPT Resources Showcase Demo apps to get inspired Blog Learnings and experiences from develo

GPT-5.5 Pro Model | OpenAI API

GPT-5.5 Pro Model | OpenAI API ChatGPT Home API Codex Docs Guides, concepts, and product docs for Codex Use cases Example workflows and tasks teams can take on with ChatGPT or Codex Docs Use cases Resources ChatGPT Apps SDK Build apps to extend ChatGPT Workspace Agents Trigger published ChatGPT workspace agents Commerce Build commerce flows in ChatGPT Ads Publish and measure ads in ChatGPT Resources Showcase Demo apps to get inspired Blog Learnings and experiences from develo