# o3

o3 is an AI model released by OpenAI on Apr 16 2025. At release it scored 26% on BullshitBench v2.

## Facts

| Field | Value |
| --- | --- |
| Model | o3 |
| Developer | OpenAI |
| Release date | Wednesday, Apr 16 2025 |
| Licensing | Proprietary |

## API pricing

All rates in USD per 1,000,000 tokens, pay-as-you-go.

| Tier | Input | Cached input | Output |
| --- | --- | --- | --- |
| All documented contexts | $2.00 | $0.50 | $8.00 |

Verified August 18, 2026 against the first-party source: https://developers.openai.com/api/docs/models/o3

## Benchmark scores published at release

| Benchmark | Score | Source | What it measures |
| --- | --- | --- | --- |
| BullshitBench v2 | 26% | Lab | Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. |

## About o3

o3, released April 16, 2025 alongside o4-mini, was OpenAI's most capable reasoning model of the o-series era and the first to combine extended reasoning with full agentic tool use in ChatGPT — searching the web, running Python, and analysing images inside its chain of thought. First previewed in December 2024 with breakthrough ARC-AGI results, it took four months to reach general availability.

In practice o3 became the model of choice for hard analytical work — mathematics, research questions, multi-step debugging — while GPT-4.1 handled everyday tasks. o3-pro followed in June 2025 for even longer reasoning budgets. The separate o-series branding ended when GPT-5 unified fast and reasoning models under one system in August 2025.

## Questions and answers

### When was o3 released?

o3 was released by OpenAI on Wednesday, Apr 16 2025.

### Who made o3?

o3 was built by OpenAI. Creators of ChatGPT and the GPT series of models. Pioneered large-scale language model research.

### How much does o3 cost?

o3 costs $2.00 per million input tokens and $8.00 per million output tokens through the OpenAI API. Cached input is $0.50 per million tokens. Rates are pay-as-you-go API prices verified against OpenAI's published pricing on August 18, 2026.

### What benchmark scores did o3 get?

o3 reports 1 tracked benchmark score — BullshitBench v2: 26%. Scores are the figures published at release by OpenAI.

### Is o3 open source?

No. o3 is a proprietary model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.

### What came before and after o3?

OpenAI's previous tracked release was GPT-4.1 nano on Apr 14 2025, 2 days earlier. It was followed by o4-mini on Apr 16 2025.


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Canonical page: https://aireleasetracker.com/model/openai/o3
Full dataset: https://aireleasetracker.com/llms-full.txt · JSON: https://aireleasetracker.com/models.json
Source: AI Release Tracker (https://aireleasetracker.com). Benchmark scores are the figures published by the releasing lab at launch.