ChatGPT Model Releases Timeline: Versions and Milestones
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Mar 2026: OpenAI API released GPT-5.4 / GPT-5.4 pro and shipped GPT-5.4 mini / nano
ChatGPT Timeline Hub: Releases, Features, and Major Events
Table of Contents
The timeline is organized into three streams:
- Model Releases
- Feature Changes
- Major Events
How to use this timeline#
Start with Model Releases for capability milestones, then check Feature Changes for practical updates, and use Major Events for ecosystem context.
2026
ChatGPT Major Events Timeline: Industry Milestones by Date
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OpenAI announced the retirement of GPT‑4o, GPT‑4.1, and GPT‑4.1 mini in ChatGPT
ChatGPT Feature Changes Timeline: Product Updates by Date
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Updated Box/Notion/Linear/Dropbox apps in Enterprise/Edu with new app actions and write capabilities (disabled by default; admin-managed)