OpenAI · OpenAI (GPT / ChatGPT)
o3
ActiveReleased 1 year ago· Apr 1, 2025Multimodal model
o-series reasoning model for hardest math/science; retiring from ChatGPT Aug 26, 2026 (API still active).
- API string
- o3
- Context window
- 200K ctx
- Knowledge cutoff
- Jan 1, 2025
- Tier
- Reasoning
- Released
- Apr 1, 2025
Release & change timeline
2 events- Deprecation
o3 retiring from ChatGPT
o3 retires from ChatGPT August 26, 2026; API access continues.
- Release
o3 released
New reasoning-model generation; topped AIME 2024 and 2025.
Part of the OpenAI (GPT / ChatGPT) version timeline. Catch Me Up — everything that changed across AI & smart home ↗