IndexChatGPT 5.4
ChatGPT 5.4
ChatGPT 5.4 and GPT-5.4 mini stopped appearing for people signed in to ChatGPT on 31 August 2026. The same models stayed available on the API, and in Codex when the session uses an API key.
Updated 2026-09-27
OpenAI’s note is the GPT-5.4 introduction, plus the later developer post that set the cutoff. If the model picker no longer lists 5.4, you are on the ChatGPT login, not on a broken account. The replacement family in chat is GPT-5.6.
Where 5.4 still runs
- API requests that pass the GPT-5.4 model id
- Codex sessions authenticated with an API key, not only a ChatGPT plan
- Not the default signed-in ChatGPT picker after 31 August 2026
Questions
Why did ChatGPT 5.4 disappear?
OpenAI removed it from signed-in ChatGPT on 31 August 2026. It was a product cutoff, not an outage.
Can I still call it from code?
Yes, on the API, until OpenAI retires that model id there too. Check the live model list before you depend on it.
Related notes
- GPT-6 and GPT-5.6
People search GPT-6 and land on OpenAI’s GPT-5.6 post. GPT-5.6 ships as Luna, Terra, and Sol. There is no separate GPT-6 product page.
- ChatGPT 5.1
ChatGPT 5.1 is an earlier ChatGPT model release. Newer pickers default to later 5.x models, including GPT-5.6.
- OpenAI API and API keys
Create an OpenAI API key at platform.openai.com. Usage is billed apart from ChatGPT Plus. new-api is a separate open-source gateway, not the official API.