Starting Friday, OpenAI will cease providing access to five legacy ChatGPT models, including the popular but controversial GPT-4o model.

The 4o model has been at the center of a number of lawsuits concerning user self-harm, delusional behavior, and AI psychosis. It remains OpenAI’s highest scoring model for sycophancy.

In addition to GPT-4o, the GPT-5, GPT-4.1, GPT-4.1 mini, and OpenAI o4-mini models have also been deprecated.

OpenAI intended to retire GPT-4o in August, when it unveiled the GPT-5 model. But at the time, there was enough backlash for OpenAI to keep the legacy model available for paid subscribers, who could manually choose to interact with that model. In a recent blog post, OpenAI noted that only 0.1% of customers have been using GPT-4o, but for a company with 800 million weekly active users, that small percentage still amounts to 800,000 people.

Thousands of users have rallied against the retirement of 4o, citing their close relationships with the model.