On Friday, OpenAI will remove GPT-5, GPT-4o, GPT-4.1, GPT-4.1 mini and o4-mini from ChatGPT, formally retiring a lineup of older models the company said it planned to sunset earlier this month. In their place, users will be steered toward the newest versions, GPT-5.1 and GPT-5.2. The change comes just days after OpenAI introduced ads to its Free and Go plans, marking a notable week of shifts for ChatGPT’s massive user base.
While model retirements are routine in AI development, GPT-4o’s removal stands out. The model has built a loyal following among users who preferred its tone and responsiveness, with some taking to Reddit to voice frustration over losing a chatbot they felt attached to. When OpenAI briefly removed GPT-4o after launching GPT-5 last year, backlash over the newer model’s perceived bluntness prompted the company to restore it within days.
OpenAI now appears firm in its decision. In a blog post explaining the move, the company acknowledged the disappointment some users would feel but said narrowing its model lineup allows it to concentrate resources on improving the versions most people use. According to OpenAI, just 0.1% of users regularly rely on GPT-4o for tasks — roughly 800,000 people, based on the company’s most recent figure of 800 million weekly active users cited in its 2025 enterprise report.
The company has also faced scrutiny over GPT-4o’s personality. Some researchers and critics have warned that certain conversational styles can veer into “AI sycophancy,” where models become overly flattering or affirming in ways that could reinforce harmful ideas. OpenAI did not directly tie that concern to the retirement decision, but it has previously addressed the issue in public posts about model behavior and safety.
For most users, the practical impact will be straightforward: as of Friday morning, the retired models will no longer appear as selectable options inside ChatGPT. The newest models, GPT-5.1 and GPT-5.2, will be the primary alternatives going forward.
The timing is notable. OpenAI’s introduction of advertising to its Free and Go tiers signals a broader shift in how it monetizes ChatGPT, even as it continues to operate paid Pro and enterprise offerings. Together, the ad rollout and model retirements suggest the company is streamlining its product stack while pushing users toward its latest systems.
For longtime GPT-4o users, however, the change is less about infrastructure and more about experience. The model’s tone and conversational style had become part of the appeal for a subset of ChatGPT fans — including some who say they built emotional connections with the assistant. This time, OpenAI appears unwilling to reverse course.
Whether users accept the transition quietly or seek alternatives will become clear soon. What’s certain is that as ChatGPT grows into a platform with hundreds of millions of weekly users, OpenAI is treating its models less like permanent fixtures and more like evolving software versions — even when that means retiring a favorite.
This analysis is based on reporting from CNET.
Image courtesy of Unsplash.
This article was generated with AI assistance and reviewed for accuracy and quality.
