# Models

> For the complete documentation index, see [llms.txt](/llms.txt)

> Choose the AI model that powers your Biel.ai chatbot.

Biel.ai supports models from OpenAI and Anthropic. Fast models are available on all plans; advanced models require a Business plan or above.

## Available models

### OpenAI

| Model | Tier | Notes |
|-------|------|-------|
| GPT-5.4 | Advanced | Latest generation with concise, focused answers. |
| GPT-5.1 | Advanced | Strong all-around performance. |
| GPT-5 | Advanced | Unified reasoning, multimodal support. |
| GPT-4.1 | Advanced | Strong on detailed and complex queries. |
| GPT-4o | Advanced | Strong on detailed and complex queries. |
| GPT-5.4 mini | Fast | Latest fast model. Tighter, faster answers than GPT-4.1 mini. |
| GPT-5 Mini | Fast | Improved capabilities over GPT-4o mini. |
| **GPT-4.1 mini (default)** | Fast | Good balance of speed and quality. |
| GPT-4o mini | Fast | Optimized for speed. |

### Anthropic

| Model | Tier | Notes |
|-------|------|-------|
| Claude Sonnet 4.6 | Advanced | Latest generation, strong on reasoning and coding. |
| Claude Sonnet 4.5 | Advanced | Strong reasoning and coding capabilities. |
| Claude Sonnet 4.0 | Advanced | Optimized for complex problem-solving. |
| Claude Sonnet 3.7 | Advanced | Nuanced, context-rich answers. |
| Claude Haiku 4.5 | Fast | Improved accuracy over Haiku 3.5. |
| Claude Haiku 3.5 | Fast | Fast and effective for general documentation. |

**Fast models** work well for high-traffic sites and straightforward queries. **Advanced models** are better for highly technical content and detailed queries.

## Which model should I pick?

Stick with the default (**GPT-4.1 mini**) unless you have a reason to switch. It handles most documentation queries well and is available on every plan.

Switch when:

| If you want... | Pick |
| -------------- | ---- |
| Faster, more concise answers | **GPT-5.4 mini** or **Claude Haiku 4.5** |
| In-depth answers for highly technical content | **GPT-5.4** or **Claude Sonnet 4.6** |

## Change the model

:::important
Only **Administrator** or **Maintainer** roles can manage projects. See [Manage roles](https://docs.biel.ai/administration/roles.md).
:::

1. In the [Biel.ai dashboard](https://app.biel.ai), select your project.
2. Click **Settings**.
3. Under **LLM settings > Select model**, choose a model from the dropdown.
4. Click **Save**.

## Data privacy

Chatbot interactions are opted out of third-party model training by default. Your data is not used to train or improve external AI models.