gpt-3.5-turbo, gpt-4, gpt-4-turbo, gpt-4.1-nano, gpt-4o-2024-05-13, gpt-image-1, o1, o1-pro, o3-mini and o4-mini shut down in the OpenAI API on October 23, 2026, with their fine-tuned versions. OpenAI names gpt-5.6-sol, gpt-5.6-terra, gpt-5.6-luna and gpt-image-2 as substitutes. Source ↗