AI EngineerGuide

o4-mini-deep-research retirement date: July 23, 2026

Retired on July 23, 2026; requests to o4-mini-deep-research-2025-06-26 now fail.

Retired on Jul 23, 2026retired
Provider
OpenAI
Model IDs affected
o4-mini-deep-research-2025-06-26, o4-mini-deep-research
Announced
April 22, 2026
Shutdown date
July 23, 2026
Replacement
gpt-5.6-sol
Platforms
Dates apply to the OpenAI API. Fine-tuned models follow the same shutdown schedule as their base model. If you use OpenAI models through another platform, check that platform's own retirement schedule.
Source
Official OpenAI deprecations page (data last changed 2026-11-02, re-checked daily)
Subscribe to all shutdowns (.ics)

Migrating from o4-mini-deep-research to GPT-5.6 Sol

Not yet reviewed. We haven't written model-specific migration notes for o4-mini-deep-research yet. Start with the provider's official guidance and the replacement's model page, and use this general checklist:

  • Search your code, config and environment variables for o4-mini-deep-research-2025-06-26, o4-mini-deep-research.
  • Re-run your evaluation set against gpt-5.6-sol before switching traffic.
  • Recount tokens with the new model's tokenizer and re-check max_tokens, context fit and cost.
  • Check tool calling, structured output and stop sequences on your real prompts.
  • Dates apply to the OpenAI API. Fine-tuned models follow the same shutdown schedule as their base model. If you use OpenAI models through another platform, check that platform's own retirement schedule.

Check your code before Jul 23

Lint a request for gpt-5.6-solPaste an API request and see every field that will return a 400 on the new model, with a fixed request. Find every o4-mini-deep-research-2025-06-26 in your codePaste code, config or an n8n workflow to list each retiring model ID by line.

Also shutting down on July 23, 2026

All model retirements · All OpenAI deprecations

FAQ

When was o4-mini-deep-research retired?

o4-mini-deep-research (o4-mini-deep-research-2025-06-26) was retired on the OpenAI API on July 23, 2026, according to the official OpenAI API deprecations page. Requests to it now fail.

What should I use instead of o4-mini-deep-research-2025-06-26?

The recommended replacement is gpt-5.6-sol.

What happens to o4-mini-deep-research-2025-06-26 requests after the shutdown date?

After a model is retired, API requests to it return an error. Move traffic to the replacement and test it on your own prompts before the date.

Does this date apply to Amazon Bedrock, Vertex AI or Azure?

Dates apply to the OpenAI API. Fine-tuned models follow the same shutdown schedule as their base model. If you use OpenAI models through another platform, check that platform’s own retirement schedule.

Which model IDs are affected?

All of these: o4-mini-deep-research-2025-06-26, o4-mini-deep-research.

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