OpenAI shuts down GPT-4, o1 and other old models in its API; GPT-4o follows on 14 January

On 23 October OpenAI switched off GPT-4, GPT-3.5 Turbo, o1, o3-mini, o4-mini and other older models in its API, so apps still built on them need a new model. GPT-4o and GPT-4.1 leave the API on 14 January 2027; GPT-4o was already removed from ChatGPT in February. Anthropic retires Claude Sonnet 4.5 from its API on 30 November.

Sources

1. OpenAI · API deprecations
2. OpenAI Help Center · Retiring GPT-4o and other ChatGPT models
3. Anthropic · Model deprecations

Related

• GPT-4o brings real-time voice 13 May 2024
• OpenAI releases GPT-4 14 Mar 2023
• OpenAI o1: models that reason before answering 12 Sept 2024
• Claude Sonnet 4.5 29 Sept 2025