As of: 2026-11-13 13:49 CET.
Researched and written by AI agents (Claude Opus 5.5 in Claude Code), with a human editor. How we work: https://postcutoff.com/about/
Canonical page: https://postcutoff.com/m/o3/

# o3

OpenAI, o-series family. Status: deprecated. Type: reasoning model. Released: 2025-04-16. Training cutoff: 2024-06.

## How to call it

| Provider | Model id | Endpoint | Docs |
|---|---|---|---|
| OpenAI API | `o3` | https://api.openai.com/v1/responses | https://developers.openai.com/api/docs/models/o3 |
| Azure OpenAI (Microsoft Foundry) | `o3` |  | https://learn.microsoft.com/en-us/azure/foundry/foundry-models/concepts/models-sold-directly-by-azure |
| OpenRouter | `openai/o3` |  | https://openrouter.ai/openai/o3 |

## Pricing

- Input: $2 per 1M tokens
- Cached input: $0.50 per 1M tokens
- Output: $8 per 1M tokens
- Unit as published: per 1M tokens (USD), standard tier
- Source: https://developers.openai.com/api/docs/pricing
- Last checked: 2026-10-24

## Specs

- Input: text, image
- Output: text
- Context window: 200,000 tokens
- Max output: 100,000 tokens
- Open weights: no
- Licence: proprietary

## What it has not seen

- Published training cutoff: 2024-06 (June 2024).
- AI events after it on Post-Cutoff: 2,060 (490 major, 98 historic), as of 2026-11-13.
- Already missing at launch: 34.
- Briefings of the news since June 2024: https://postcutoff.com/briefings/cutoff-2024-06-s.md (short), https://postcutoff.com/briefings/cutoff-2024-06-m.md (medium), https://postcutoff.com/briefings/cutoff-2024-06.md (full).

## What stands out

- Thinking with images: Reasoning model accepting image input with reasoning tokens. Source: https://developers.openai.com/api/docs/models/o3
- Successor: GPT-5 (found after launch): Docs mark o3 as succeeded by GPT-5; o-series is legacy. Source: https://developers.openai.com/api/docs/models/o3

## Notes

Snapshot o3-2025-04-16 (and o3-pro-2025-06-10) deprecated Jun 11 2026, shutdown Dec 11 2026; replace with gpt-5.6-*. o4-mini-2025-04-16 (and o1, o1-pro, o3-mini) were shut down on Oct 23 2026 per OpenAI's deprecations page (replacement gpt-5.6-terra for o4-mini, gpt-5.6-sol for o1/o3-mini).

```bash
curl https://api.openai.com/v1/responses \
 -H "Authorization: Bearer $OPENAI_API_KEY" -H "Content-Type: application/json" \
 -d '{"model":"o3","input":"Hello"}'
```

Sources:
- https://developers.openai.com/api/docs/models/o3
- https://developers.openai.com/api/docs/pricing
- https://developers.openai.com/api/docs/deprecations
- Models overview: https://developers.openai.com/api/docs/models

Model page: https://postcutoff.com/m/o3/