# OpenAI o3 — deprecation status

> Yes — OpenAI deprecated o3 on June 11, 2026 and shuts it down on December 11, 2026 (in 134 days). The recommended replacement is GPT-5.6 Sol.

The reasoning model that made chain-of-thought a product feature rather than a prompting trick, and the last o-series flagship before the line was folded into GPT-5. It outlived o1 by more than a year and is still widely referenced in evaluation code and papers.

## Facts

| Field | Value |
| --- | --- |
| Provider | OpenAI |
| Model id | `o3` |
| Status | Deprecated |
| Aliases | `o3-2025-04-16` |
| Released | April 16, 2025 |
| Deprecated | June 11, 2026 |
| Shutdown | December 11, 2026 (in 134 days) |
| Last verified | July 30, 2026 |

## Replacement

- **GPT-5.6 Sol** (`gpt-5.6-sol`) · recommended — https://modeldeprecations.dev/openai/gpt-5.6-sol
  - Both are reasoning models, so max_completion_tokens and reasoning_effort carry over. Reasoning tokens are billed as output on both, which is the line item to compare.
  - Parameters it accepts: https://modelparams.dev/models/openai/gpt-5.6-sol

```diff
- "model": "o3"
+ "model": "gpt-5.6-sol"
```

## FAQ

### When will OpenAI o3 shut down?

OpenAI o3 is scheduled to shut down on December 11, 2026, in 134 days.

### What replaces OpenAI o3?

OpenAI recommends GPT-5.6 Sol (`gpt-5.6-sol`) as the replacement for OpenAI o3. Both are reasoning models, so max_completion_tokens and reasoning_effort carry over. Reasoning tokens are billed as output on both, which is the line item to compare.

### Is OpenAI o3 still available?

Yes, for now. OpenAI o3 is deprecated but still answers requests until December 11, 2026. Deprecated models get no further updates and are the first to lose capacity.

### How do I migrate from OpenAI o3 to gpt-5.6-sol?

Swap the model id in your API call: replace "o3" with "gpt-5.6-sol". Both are reasoning models, so max_completion_tokens and reasoning_effort carry over. Reasoning tokens are billed as output on both, which is the line item to compare.

### Does this apply to o3-2025-04-16 too?

Yes. OpenAI o3 is also published as `o3-2025-04-16`; that id shares the same lifecycle dates as `o3`.

## Sources

- [OpenAI API deprecations](https://developers.openai.com/api/docs/deprecations) — accessed 2026-07-30

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Canonical page: https://modeldeprecations.dev/openai/o3
JSON: https://modeldeprecations.dev/api/v1/models/openai/o3.json