When was OpenAI o3 released?
OpenAI publicly released o3 on April 16, 2025. The announcement says it was releasing o3 that day. (openai.com)
o3 and o3-mini have different release dates
- o3-mini: January 31, 2025. OpenAI said it was available in ChatGPT and the API that day. (
openai.com) - o3: April 16, 2025. OpenAI said o3 was available to developers that day through the Chat Completions API and Responses API. Some developers needed to verify their organizations to access the models. (
openai.com)
So the release date for o3 is April 16, 2025—not o3-mini’s January date.
Is o3 still available for a production API integration?
As of November 12, 2026, OpenAI marks o3 and the o3-2025-04-16 snapshot as deprecated in the API. The scheduled API shutdown date is December 11, 2026; as of November 12, that date is still in the future. This API lifecycle is separate from o3’s ChatGPT availability. Check OpenAI’s o3 model documentation and API deprecation schedule for the current status of the exact model ID you use. (developers.openai.com)
In brief: o3 was publicly released on April 16, 2025, and API access was available that day through Chat Completions and Responses, subject to organization verification for some developers. o3-mini launched earlier, on January 31, 2025.