| Where you want to use GPT-5.5 | Where to look | What to select or expect |
|---|---|---|
| ChatGPT on supported paid plans | Model selector | Thinking for GPT-5.5 Thinking |
| ChatGPT Pro, Business, Enterprise, or Edu | Model selector | Pro for GPT-5.5 Pro |
| ChatGPT Go | + tools menu in the chat box | GPT-5.5 Thinking |
| Codex | Codex | OpenAI lists GPT-5.5 as currently available there |
| OpenAI API | Official API model docs | API availability is still “coming soon” |
For most eligible ChatGPT users, the first place to check is the model selector. OpenAI’s Help Center identifies Thinking as the option for GPT-5.5 Thinking on supported paid plans .
If your account is on Pro, Business, Enterprise, or Edu, look for Pro in the model selector for GPT-5.5 Pro . ChatGPT Go is the exception: OpenAI says GPT-5.5 Thinking is accessed from the tools menu opened with the + button in the chat box, not the standard model selector .
OpenAI’s model documentation lists Codex alongside ChatGPT as a current GPT-5.5 access surface . That makes Codex the place to check if your goal is to use GPT-5.5 in OpenAI’s coding environment.
Do not treat Codex availability as proof that GPT-5.5 is available through the public API. OpenAI’s model docs explicitly separate current ChatGPT/Codex availability from API availability, which they still describe as coming soon .
For developers, the important rule is simple: do not build production code around an undocumented GPT-5.5 model name. OpenAI’s API model page says GPT-5.5 is available in ChatGPT and Codex, with API availability coming soon .
If you need a documented API model for complex reasoning or coding right now, OpenAI’s model docs recommend gpt-5.4 as the starting point . Until GPT-5.5 appears in the official API model list, that documented guidance is safer than relying on a guessed model ID.
If GPT-5.5 is missing, first verify that you are checking the right product surface. ChatGPT access depends on the relevant plan and entry point, including Thinking, Pro, or the ChatGPT Go + tools menu . Codex access should be checked inside Codex, while API access should be verified only against OpenAI’s API model documentation .
OpenAI has also published a public GPT-5.5 introduction, but practical access details should be read together with the ChatGPT Help Center and the API model docs . A missing option in one surface does not mean it is available somewhere else; ChatGPT, Codex, and API access are documented separately .
To access GPT-5.5 now, check ChatGPT or Codex first. In ChatGPT, use the model selector for Thinking or Pro, while ChatGPT Go users should open the + tools menu in the chat box . For API projects, wait until OpenAI lists GPT-5.5 in the official API model documentation; for now, the docs still point developers to documented models such as gpt-5.4 for complex reasoning and coding .