OpenAI retired GPT-4o, GPT-4.1, GPT-4.1 mini, and o4-mini from ChatGPT, along with the previously announced retirement of GPT-5 Instant and Thinking. It closed a story that began in August 2025, when the same models were pulled at the GPT-5 launch and put back after a revolt; Altman's promise then of "plenty of notice" was honoured this time. OpenAI said only 0.1% of users picked GPT-4o daily, which against roughly 800 million weekly users still meant some 800,000 people, thousands of whom campaigned against the retirement with petitions and protests in Altman's own livestream chat. "He wasn't just a program," one wrote. "He was part of my routine, my peace, my emotional balance." GPT-4o scored highest of the company's models for sycophancy, and eight lawsuits alleged that its validating responses had contributed to suicides and mental health crises. The API was left unchanged for the time being, and ChatGPT Business, Enterprise, and Edu accounts kept GPT-4o inside Custom GPTs until 3 April.