OpenAI announced in its latest ChatGPT release notes that it's retiring the o3 and GPT-4.5 models from the ChatGPT web and mobile interfaces, part of a broader effort to streamline its product line and focus resources on the newer GPT-5.5 family (GPT-5.5 Instant, GPT-5.5 Thinking, and GPT-5.5 Pro).
The move cleans out older, lower-usage models so the company can concentrate computing power and engineering talent on its flagship series. Here's the retirement schedule:
- GPT-4.5 enters a 30-day transition period and will be officially removed on June 27, 2026.
- OpenAI o3 enters a 90-day transition period and will be officially removed on August 26, 2026.
Until those deadlines, ChatGPT paying subscribers can still manually select the models in settings. And developers don't need to worry — OpenAI's API will continue to support both o3 and GPT-4.5 for now.