# o3

> For the complete documentation index, see [llms.txt](/llms.txt). Markdown versions of documentation pages are available by appending `.md` to the page URL.

> Reasoning model for complex tasks, succeeded by GPT-5

Model ID: `o3`

o3 is a well-rounded and powerful model across domains. It sets a new 
standard for math, science, coding, and visual reasoning tasks. It also 
excels at technical writing and instruction-following. Use it to think 
through multi-step problems that involve analysis across text, code, and images. 

o3 is succeeded by [GPT-5](/api/docs/models/gpt-5).

Learn more about how to use our reasoning models in our 
[reasoning](/api/docs/guides/reasoning?api-mode=responses) guide.

## Model details

- Default snapshot: `o3-2025-04-16`
- Input modalities: text, image
- Output modalities: text
- 200,000 context window
- 100,000 max output tokens
- Jun 01, 2024 knowledge cutoff
- Reasoning token support

## Pricing

Pricing is based on the number of tokens used, or other metrics based on the model type. For tool-specific models, like search and computer use, there’s a fee per tool call. See details in the [pricing page](/api/docs/pricing).

### Text tokens

| Metric | Price | Unit |
| --- | ---: | --- |
| Input | $2 | 1M tokens |
| Cached input | $0.5 | 1M tokens |
| Output | $8 | 1M tokens |

### Text tokens

| Metric | Price | Unit |
| --- | ---: | --- |
| Input | $1 | 1M tokens |
| Cached input | $0.25 | 1M tokens |
| Output | $4 | 1M tokens |

## Endpoints

| Endpoint | Route | Support |
| --- | --- | --- |
| Live | `v1/live/sessions` | Not supported |
| Chat Completions | `v1/chat/completions` | Supported |
| Responses | `v1/responses` | Supported |
| Realtime | `v1/realtime` | Not supported |
| Realtime translation | `v1/realtime/translations` | Not supported |
| Realtime transcription | `v1/realtime/transcription_sessions` | Not supported |
| Assistants | `v1/assistants` | Not supported |
| Batch | `v1/batch` | Supported |
| Fine-tuning | `v1/fine-tuning` | Not supported |
| Embeddings | `v1/embeddings` | Not supported |
| Image generation | `v1/images/generations` | Not supported |
| Videos | `v1/videos` | Not supported |
| Image edit | `v1/images/edits` | Not supported |
| Speech generation | `v1/audio/speech` | Not supported |
| Transcription | `v1/audio/transcriptions` | Not supported |
| Translation | `v1/audio/translations` | Not supported |
| Moderation | `v1/moderations` | Not supported |
| Completions (legacy) | `v1/completions` | Not supported |

## Supported features

- streaming
- structured_outputs
- file_search
- function_calling
- file_uploads
- image_input
- prompt_caching
- evals
- stored_completions

## Supported tools

Tools supported by this model when using the Responses API.

- function_calling
- file_search
- image_generation
- code_interpreter
- mcp
- web_search

## Quick comparison

| Model | Input | Cached input | Output |
| --- | ---: | ---: | ---: |
| o3 | $2 | $0.5 | $8 |
| o1 | $15 | $7.5 | $60 |
| o4-mini | $1.1 | $0.275 | $4.4 |

## Snapshots

Snapshots let you lock in a specific version of the model so that performance and behavior remain consistent. Below is a list of all available snapshots and aliases for o3.

- `o3-2025-04-16`

## Rate limits

Rate limits ensure fair and reliable access to the API by placing specific caps on requests, tokens, audio duration, or other usage within a given time period. Your usage tier determines how high these limits are set and automatically increases as you send more requests and spend more on the API.

### default

| Tier | RPM | TPM | Batch queue limit |
| --- | ---: | ---: | ---: |
| Tier 1 | 500 | 30,000 | 90,000 |
| Tier 2 | 5,000 | 450,000 | 1,350,000 |
| Tier 3 | 5,000 | 800,000 | 50,000,000 |
| Tier 4 | 10,000 | 2,000,000 | 200,000,000 |
| Tier 5 | 10,000 | 30,000,000 | 5,000,000,000 |