GPT-5.1 arrived in ChatGPT to amazement at its speed and did not last four months there
In November 2025, people were struck by how quickly GPT-5.1, OpenAI’s “more conversational” model, arrived. By 11 March 2026 it had already disappeared from ChatGPT.
On 12 November 2025, in ChatGPT-IA-edu, OpenAI’s announcement was shared: GPT-5.1 was reaching all ChatGPT users that week, smarter, more reliable and more conversational. The reaction was amazement at the speed of the rollout.
A month later, on 11 December, GPT-5.2 came out, and on 5 March 2026, GPT-5.4. Six days after that, according to OpenAI’s page on retired models, GPT-5.1 Instant, Thinking and Pro left ChatGPT, and their conversations and custom GPTs moved to GPT-5.3 Instant and GPT-5.4 Thinking or Pro. They remain only in the API.
For the classroom, the lesson goes beyond a name: a custom GPT or a set of instructions fine-tuned for a certain tone can end up tied to a model that, a few months later, is no longer there. What a year ago was the news of the week is today a line in a list of retirements.
GPT-5.1 arrived in ChatGPT to amazement at its speed and did not last four months there
In November 2025, people were struck by how quickly GPT-5.1, OpenAI’s “more conversational” model, arrived. By 11 March 2026 it had already disappeared from ChatGPT.
On 12 November 2025, in ChatGPT-IA-edu, OpenAI’s announcement was shared: GPT-5.1 was reaching all ChatGPT users that week, smarter, more reliable and more conversational. The reaction was amazement at the speed of the rollout.
A month later, on 11 December, GPT-5.2 came out, and on 5 March 2026, GPT-5.4. Six days after that, according to OpenAI’s page on retired models, GPT-5.1 Instant, Thinking and Pro left ChatGPT, and their conversations and custom GPTs moved to GPT-5.3 Instant and GPT-5.4 Thinking or Pro. They remain only in the API.
For the classroom, the lesson goes beyond a name: a custom GPT or a set of instructions fine-tuned for a certain tone can end up tied to a model that, a few months later, is no longer there. What a year ago was the news of the week is today a line in a list of retirements.
