> For the complete documentation index, see [llms.txt](https://morphic.com/docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://morphic.com/docs/getting-started/copilot/choose-a-model.md).

# Choose a model

How to pick which model runs a Copilot chat, what each one is suited to, and where to set the one new chats start with.

Copilot runs on a language model, and you can pick which one. It is the model that reads your request, plans the work, and talks back to you. Which image or video model makes the media is a separate setting, under 'Model preferences' in the prompt bar.

## The models

| Model       | Suited to                                                  |
| ----------- | ---------------------------------------------------------- |
| Auto        | Picks the best model for each task. The default            |
| Sonnet 4.6  | Balanced intelligence and speed for most tasks             |
| Grok 4.5    | Fast, direct responses for everyday tasks                  |
| GPT 5.6 Sol | Deep reasoning for complex, multi-step tasks               |
| Fable 5.1   | Creative, polished responses for storytelling and ideation |

Leave it on 'Auto' unless you have a reason not to. GPT 5.6 Sol and Fable 5.1 need a paid plan. Some models are listed but dimmed; those cannot be picked yet.

## Pick one for a chat

1. Open [Copilot](https://studio.morphic.com/chat)
2. Click the button at the bottom right of the prompt bar. It reads mode first and model second, so 'Auto · Sonnet 4.6' is automatic generation running on Sonnet 4.6
3. Under 'Model', open the dropdown and pick one. A checkmark marks the active model

The choice belongs to the chat, so chats can run on different models at once, and it holds until you change it.

## Set the default for new chats

1. Open ['Preferences'](https://studio.morphic.com/settings/preferences)
2. Beside 'Default chat mode', open the dropdown
3. Pick the model under 'Model', and the mode under 'Mode' while you are there

New chats start on that model. Changing one chat's model does not change the default.

That's how you choose a model on Morphic. Most work is fine on 'Auto'; pick one yourself when a chat calls for speed or for more reasoning.

***

If you have any trouble or have any questions, feel free to reach out. We're happy to help. Write to us at [**support@morphic.com**](mailto:support@morphic.com)**.**


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://morphic.com/docs/getting-started/copilot/choose-a-model.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.