IndexChatGPT 5.1
ChatGPT 5.1
ChatGPT 5.1 is a previous model in the ChatGPT picker, documented when OpenAI shipped it. New chats now default to later 5.x models.
Updated 2026-09-27
The announcement is GPT-5.1. Use it as the record of what that release added. Do not assume the picker still offers 5.1 on every plan. After 5.4 left the signed-in app on 31 August 2026, the named successor family is GPT-5.6.
If a tutorial says “select 5.1” and the menu does not list it, pick the current default and re-test the prompt. Model behavior changes enough that a 5.1 prompt is not a guarantee on 5.6.
Questions
Is ChatGPT 5.1 the newest model?
No. It is an earlier release. GPT-5.6 is the later family people reach when they search for a newer GPT.
Related notes
- ChatGPT 5.4
ChatGPT 5.4 and 5.4 mini left the signed-in ChatGPT app on 31 August 2026. Both remain on the API and on Codex sessions that use an API key.
- 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.
- How much is ChatGPT?
ChatGPT Plus is $20 a month. Pro is listed at $100 and $200, with new $200 sign-ups paused. API usage is a separate bill.