OpenAI’s initial significant upgrade to ChatGPT, GPT-4, which was released months ago, is being phased out. According to a changelog published by the company on Thursday, the model will be retired from ChatGPT on April 30. It will be replaced by GPT-4o, which has been available since last May.

Although GPT-4 has played a significant role in the brief but world-changing history of modern AI, its retirement will not have a significant impact on customers. OpenAI claims that GPT-4o offers improvements in writing, coding, and STEM fields. Recent updates have further enhanced the capabilities of the newer model, including its ability to follow instructions, solve problems, and engage in conversations. The company describes GPT-4o, a multimodal model, as the “natural successor” to the soon-to-be-retired GPT-4.

Despite its impending removal from ChatGPT, users of the API will still have access to GPT-4 after April 30.

The announcement coincides with OpenAI’s reported plans to launch a range of new models. Reverse engineer Tibor Blaho posted images on Friday (via TechCrunch) that appear to confirm the development of o3, o4-mini, and GPT-4.1 models (including nano and mini offshoots). In February, the company introduced a research preview of GPT-4.5, a more advanced and natural conversationalist that will serve as a stepping stone to GPT-5.

The release notes from OpenAI acknowledged the significant role GPT-4 played in the company’s development. “GPT‑4 marked a pivotal moment in ChatGPT’s evolution,” the notes stated. “We appreciate the breakthroughs it enabled and the feedback that helped shape its successor. GPT‑4o builds on that foundation to deliver even greater capability, consistency, and creativity.”