OpenAI

GPT-5.4 Thinking and GPT-5.4 Pro are rolling out now in ChatGPT. GPT-5.4 is also now available in the API and Codex. GPT-5.4 brings our advances in reasoning, coding, and agentic workflows into one frontier model.

Sharing some of the work I’ve been doing at OpenAI: we now monitor 99.9% of internal coding traffic for misalignment using our most powerful models, reviewing full trajectories to catch suspicious behavior, escalate serious cases quickly, and strengthen our safeguards over time.

Are you up for a challenge? openai.com/parameter-golf

GPT-5.4 nano is is also available starting today in the API.

GPT-5.4 mini is available today in ChatGPT, Codex, and the API. Optimized for coding, computer use, multimodal understanding, and subagents. And it’s 2x faster than GPT-5 mini. openai.com/index/introduc…

Listen to the OpenAI Podcast on— Spotify open.spotify.com/show/0zojMEDiz… Apple podcasts.apple.com/us/podcast/ope… YouTube youtu.be/VAzryGwnJW8

AI is starting to help solve real issues in healthcare for patients and doctors. OpenAI’s Head of Health Dr. Nate Gross and Health AI Research Lead Karan Singhal join @AndrewMayne to discuss how we're building new models and products to meet the world's health needs.

Developers coming from other tools are often impressed by what Codex finds in code review. In this video, @majatrebacz and I show how to set it up and walk through issues Codex finds in real PRs. Included with ChatGPT Plus/Pro (or ~$1/run with credits).

We’re acquiring Promptfoo. Their technology will strengthen agentic security testing and evaluation capabilities in OpenAI Frontier. Promptfoo will remain open source under the current license, and we will continue to service and support current customers. openai.com/index/openai-t…

Codex Security—our application security agent—is now in research preview. openai.com/index/codex-se…

Construction is underway at our site in Port Washington, Wisconsin. This is an important step in our long-term compute strategy. Grateful to our partners @VantageDC and @Oracle who are helping bring this capacity online. We’re been making rapid progress expanding the infrastructure behind OpenAI. Last week we announced an expansion of our foundational work with @NVIDIA systems that will power the next generation of models. We also shared how we're continuing to deepen our work across the ecosystem, including lean in further with @awscloud. Building world-class AI requires world-class infrastructure. Excited to see the work happening on the ground in Wisconsin and grateful to the teams and partners helping make it happen.

We're publishing a new evaluation suite and research paper on Chain-of-Thought (CoT) Controllability. We find that GPT-5.4 Thinking shows low ability to obscure its reasoning—suggesting CoT monitoring remains a useful safety tool. openai.com/index/reasonin…

GPT-5.4 Thinking and Pro are rolling out gradually starting today across ChatGPT, the API, and Codex. openai.com/index/introduc…

GPT-5.4 is our most factual and efficient model: fewer tokens, faster speed. In ChatGPT, GPT-5.4 Thinking has improved deep web research, better context retention when it thinks for longer—and oh—you can now interrupt the model and add instructions or adjust its direction mid-response. Steering is available this week on Android and web. iOS coming soon.

GPT-5.4 Thinking and GPT-5.4 Pro are rolling out now in ChatGPT. GPT-5.4 is also now available in the API and Codex. GPT-5.4 brings our advances in reasoning, coding, and agentic workflows into one frontier model.

🧵1/ We've brought the most advanced AI to Prism by introducing Codex to Prism. Prism is already the best place for scientific writing to happen—and with Codex, now you can write, compute, analyze, and iterate all in one place.

The Codex app is now on Windows. Get the full Codex app experience on Windows with a native agent sandbox and support for Windows developer environments in PowerShell. developers.openai.com/wendows

5.4 sooner than you Think.

GPT-5.3 Instant gives you more accurate answers. When using web search, you also get: - Sharper contextualization - Better understanding of question subtext - More consistent response tone within the chat

GPT-5.3 Instant also has fewer unnecessary refusals and preachy disclaimers.

GPT-5.3 Instant in ChatGPT is now rolling out to everyone. More accurate, less cringe. openai.com/index/gpt-5-3-…