# o1 Preview API Pricing

As of October 10, 2026, o1 Preview costs $16.50 per 1M input tokens and $66.00 per 1M output tokens on Azure OpenAI, with cache reads at $8.25 per 1M tokens. It has a 128,000-token context window and returns up to 32,768 tokens per response.

- Page: https://models.litellm.ai/models/o1-preview
- Lab: OpenAI
- LiteLLM model name: `azure/eu/o1-preview`
- Context window: 128,000 tokens
- Max output: 32,768 tokens
- Added to LiteLLM: September 2024
- Deprecation date: July 28, 2025
- Prices updated: October 10, 2026

## Pricing by provider

Token prices in USD per 1M tokens.

| Provider | Model name | Input | Output | Cache read | Per image | Per second | Context |
|---|---|---|---|---|---|---|---|
| Azure OpenAI (eu) | `azure/eu/o1-preview` | $16.50 | $66.00 | $8.25 | – | – | 128K |
| Azure OpenAI (us) | `azure/us/o1-preview` | $16.50 | $66.00 | $8.25 | – | – | 128K |

## Cost examples

1,000 requests with 2,000 input and 500 output tokens each:

- Azure OpenAI: $66.00

100 long-document requests with 100,000 input and 2,000 output tokens each:

- Azure OpenAI: $178.20

## Features

Supported: Prompt caching.

## Use it with LiteLLM

```python
from litellm import completion

response = completion(
    model="azure/eu/o1-preview",
    messages=[{"role": "user", "content": "Hello!"}],
)
```

## FAQ

### How much does o1 Preview cost?

o1 Preview costs $16.50 per 1M input tokens and $66.00 per 1M output tokens on Azure OpenAI, with cache reads at $8.25 per 1M tokens.

### What is the context window of o1 Preview?

o1 Preview has a 128,000-token context window and returns up to 32,768 tokens per response.

### Which providers offer o1 Preview?

o1 Preview is available from Azure OpenAI through LiteLLM, using the model name azure/eu/o1-preview.

### How do I call o1 Preview with an OpenAI-compatible API?

Use the LiteLLM Python SDK with model="azure/eu/o1-preview", or add the model to the LiteLLM proxy's config.yaml and send requests to /v1/chat/completions from any OpenAI client. LiteLLM tracks the cost of every request at the prices on this page.

### What features does o1 Preview support?

o1 Preview supports prompt caching.

### When did LiteLLM add o1 Preview?

o1 Preview was added to LiteLLM's model price file in September 2024.

### Is o1 Preview being deprecated?

Azure OpenAI deprecated azure/eu/o1-preview on July 28, 2025.

Source: LiteLLM model price file, https://github.com/BerriAI/litellm/blob/main/model_prices_and_context_window.json