OpenAI will retire GPT‑4o, GPT‑4.1, GPT‑4.1 mini and OpenAI o4‑mini in ChatGPT on 13 February 2026, alongside the previously announced retirement of GPT‑5 (Instant and Thinking). The aim is a faster, more reliable experience while focusing resources on current models. No API changes at this time.

What’s Changing & Why

Which models are leaving? GPT‑4o, GPT‑4.1, GPT‑4.1 mini and OpenAI o4‑mini leave ChatGPT on 13 Feb 2026. GPT‑5 (Instant & Thinking) retirement was announced earlier.
Why retire models? Consolidation improves reliability, performance and support, allowing investment in the latest models and features.
API status: The retirement applies to ChatGPT; no API changes for now. If you depend on legacy model snapshots in the API, monitor the deprecations page and Azure notices.

Practical Guidance (Users & Admins)

Individuals (ChatGPT):

• You don’t need to take action. Your conversations will continue to work; newer default models will be used.

• If you liked a legacy model’s tone, update Custom Instructions to guide style and behaviour.

Workspace admins:

• Communicate the change and suggest updated templates/prompts.

• Review any team playbooks referencing specific legacy model names.

• For regulated teams, update screenshots/process docs showing the model switcher.

Developers:

• For API apps, check the Deprecations page periodically. If using Azure OpenAI, note separate retirement timelines and auto‑upgrade plans.

Example Transitions

• From GPT‑4o → GPT‑5.2: Re‑test saved prompts; add tone instructions (e.g., concise, warm, British English).

• From GPT‑4.1 mini → current lightweight model: Validate latency/quality; adjust temperature and max tokens if needed.

• From o4‑mini → current “o‑class” replacement: Confirm tool‑use behaviours and output formats.

Risks & Good Practice

• Expectation drift: Legacy models may have had distinct “feel.” Capture style via instructions/examples.

• Evaluation: Re‑run quick acceptance tests on key prompts (accuracy, format, latency).

• Change control: Document model settings; pin versions where supported; keep rollback notes for prompts.

FAQs

What models are being retired?
GPT‑4o, GPT‑4.1, GPT‑4.1 mini and OpenAI o4‑mini leave ChatGPT on 13 February 2026. GPT‑5 (Instant/Thinking) retirement was previously announced.

Why is OpenAI retiring these models?
To streamline the experience, improve performance and reliability, and focus resources on newer models.

Will there be changes to the API?
No changes at this time for the API; continue to monitor official deprecation notices for snapshots and Azure timelines.

How will this affect users?
Most users won’t need to act. The default model selection will shift to current versions, with improved performance and stability.

How can I preserve a legacy model’s tone?
Use Custom Instructions and a short style block (examples of tone, phrasing, and do/don’t rules) to approximate previous behaviour.